The R13B03 release.OTP_R13B03

31 files changed, 31896 insertions, 0 deletions

diff --git a/lib/ssh/doc/html/.gitignore b/lib/ssh/doc/html/.gitignore
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/lib/ssh/doc/html/.gitignore
diff --git a/lib/ssh/doc/man3/.gitignore b/lib/ssh/doc/man3/.gitignore
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/lib/ssh/doc/man3/.gitignore
diff --git a/lib/ssh/doc/pdf/.gitignore b/lib/ssh/doc/pdf/.gitignore
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/lib/ssh/doc/pdf/.gitignore
diff --git a/lib/ssh/doc/src/Makefile b/lib/ssh/doc/src/Makefile
new file mode 100644
index 0000000000..d2907a39d7
--- /dev/null
+++ b/lib/ssh/doc/src/Makefile
@@ -0,0 +1,205 @@
+#
+# %CopyrightBegin%
+# 
+# Copyright Ericsson AB 2004-2009. All Rights Reserved.
+# 
+# The contents of this file are subject to the Erlang Public License,
+# Version 1.1, (the "License"); you may not use this file except in
+# compliance with the License. You should have received a copy of the
+# Erlang Public License along with this software. If not, it can be
+# retrieved online at http://www.erlang.org/.
+# 
+# Software distributed under the License is distributed on an "AS IS"
+# basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+# the License for the specific language governing rights and limitations
+# under the License.
+# 
+# %CopyrightEnd%
+#
+
+#
+include $(ERL_TOP)/make/target.mk
+include $(ERL_TOP)/make/$(TARGET)/otp.mk
+
+# ----------------------------------------------------
+# Application version
+# ----------------------------------------------------
+include ../../vsn.mk
+VSN=$(SSH_VSN)
+APPLICATION=ssh
+
+# ----------------------------------------------------
+# Include dependency
+# ----------------------------------------------------
+
+
+ifndef DOCSUPPORT
+include make.dep
+endif 
+
+# ----------------------------------------------------
+# Release directory specification
+# ----------------------------------------------------
+RELSYSDIR = $(RELEASE_PATH)/lib/$(APPLICATION)-$(VSN)
+
+# ----------------------------------------------------
+# Target Specs
+# ----------------------------------------------------
+XML_APPLICATION_FILES = ref_man.xml
+XML_REF3_FILES = \
+	ssh.xml \
+	ssh_channel.xml \
+	ssh_connection.xml\
+	ssh_sftp.xml \
+	ssh_sftpd.xml \
+
+XML_PART_FILES = part_notes.xml  part_notes_history.xml 
+XML_CHAPTER_FILES = notes.xml notes_history.xml
+
+BOOK_FILES = book.xml
+
+# ----------------------------------------------------
+
+HTML_FILES = $(XML_APPLICATION_FILES:%.xml=$(HTMLDIR)/%.html) \
+	$(XML_PART_FILES:%.xml=$(HTMLDIR)/%.html)
+
+INFO_FILE = ../../info
+EXTRA_FILES = \
+	$(DEFAULT_GIF_FILES) \
+	$(DEFAULT_HTML_FILES) \
+	$(XML_REF3_FILES:%.xml=$(HTMLDIR)/%.html) \
+	$(XML_CHAPTER_FILES:%.xml=$(HTMLDIR)/%.html)
+
+#	notes_history.html \
+
+
+MAN3_FILES = $(XML_REF3_FILES:%.xml=$(MAN3DIR)/%.3)
+
+
+ifdef DOCSUPPORT
+
+HTML_REF_MAN_FILE = $(HTMLDIR)/index.html
+
+TOP_PDF_FILE = $(PDFDIR)/$(APPLICATION)-$(VSN).pdf
+
+else
+
+TEX_FILES_BOOK = \
+	$(BOOK_FILES:%.xml=%.tex)
+TEX_FILES_REF_MAN = $(XML_REF3_FILES:%.xml=%.tex) \
+	$(XML_APPLICATION_FILES:%.xml=%.tex)
+TEX_FILES_USERS_GUIDE = \
+	$(XML_CHAPTER_FILES:%.xml=%.tex)
+
+TOP_PDF_FILE = $(APPLICATION)-$(VSN).pdf
+TOP_PS_FILE  = $(APPLICATION)-$(VSN).ps
+
+$(TOP_PDF_FILE): book.dvi ../../vsn.mk
+	$(DVI2PS) $(DVIPS_FLAGS) -f $< | $(DISTILL) $(DISTILL_FLAGS) > $@
+
+$(TOP_PS_FILE): book.dvi ../../vsn.mk
+	$(DVI2PS) $(DVIPS_FLAGS) -f $< > $@
+
+endif 
+
+# ----------------------------------------------------
+# FLAGS 
+# ----------------------------------------------------
+XML_FLAGS += 
+DVIPS_FLAGS += 
+
+# ----------------------------------------------------
+# Targets
+# ----------------------------------------------------
+$(HTMLDIR)/%.gif: %.gif
+	$(INSTALL_DATA) $< $@
+
+ifdef DOCSUPPORT
+
+docs: pdf html man
+
+$(TOP_PDF_FILE): $(XML_FILES)
+
+pdf: $(TOP_PDF_FILE)
+
+html: $(HTML_REF_MAN_FILE)
+
+clean clean_docs:
+	rm -rf $(HTMLDIR)/*
+	rm -f $(MAN3DIR)/*
+	rm -f $(TOP_PDF_FILE) $(TOP_PDF_FILE:%.pdf=%.fo)
+	rm -f errs core *~
+
+else
+
+ifeq ($(DOCTYPE),pdf)
+docs: pdf
+else
+ifeq ($(DOCTYPE),ps)
+docs: ps
+else
+docs: html man
+endif
+endif
+
+pdf: $(TOP_PDF_FILE)
+
+ps: $(TOP_PS_FILE)
+
+html: $(HTML_FILES)
+
+clean clean_docs clean_tex:
+	rm -f $(TEX_FILES_USERS_GUIDE) $(TEX_FILES_REF_MAN) $(TEX_FILES_BOOK)
+	rm -f $(HTML_FILES) $(MAN3_FILES)
+	rm -f $(TOP_PDF_FILE) $(TOP_PS_FILE)
+	rm -f errs core *~ *xmls_output *xmls_errs $(LATEX_CLEAN) 
+
+endif
+
+man: $(MAN3_FILES)
+
+
+debug opt: 
+
+
+# ----------------------------------------------------
+# Release Target
+# ---------------------------------------------------- 
+include $(ERL_TOP)/make/otp_release_targets.mk
+
+ifdef DOCSUPPORT
+
+release_docs_spec: docs
+	$(INSTALL_DIR) $(RELSYSDIR)/doc/pdf
+	$(INSTALL_DATA) $(TOP_PDF_FILE) $(RELSYSDIR)/doc/pdf
+	$(INSTALL_DIR) $(RELSYSDIR)/doc/html
+	$(INSTALL_DATA) $(HTMLDIR)/* \
+		$(RELSYSDIR)/doc/html
+	$(INSTALL_DATA) $(INFO_FILE) $(RELSYSDIR)
+	$(INSTALL_DIR) $(RELEASE_PATH)/man/man3
+	$(INSTALL_DATA) $(MAN3DIR)/* $(RELEASE_PATH)/man/man3
+else
+
+ifeq ($(DOCTYPE),pdf)
+release_docs_spec: pdf
+	$(INSTALL_DIR) $(RELEASE_PATH)/pdf
+	$(INSTALL_DATA) $(TOP_PDF_FILE) $(RELEASE_PATH)/pdf
+else
+ifeq ($(DOCTYPE),ps)
+release_docs_spec: ps
+	$(INSTALL_DIR) $(RELEASE_PATH)/ps
+	$(INSTALL_DATA) $(TOP_PS_FILE) $(RELEASE_PATH)/ps
+else
+release_docs_spec: docs
+	$(INSTALL_DIR) $(RELSYSDIR)/doc/html
+	$(INSTALL_DATA) $(EXTRA_FILES) $(HTML_FILES) \
+		$(RELSYSDIR)/doc/html
+	$(INSTALL_DATA) $(INFO_FILE) $(RELSYSDIR)
+	$(INSTALL_DIR) $(RELEASE_PATH)/man/man3
+	$(INSTALL_DATA) $(MAN3_FILES) $(RELEASE_PATH)/man/man3
+endif
+endif
+
+endif
+
+release_spec:
diff --git a/lib/ssh/doc/src/book.xml b/lib/ssh/doc/src/book.xml
new file mode 100644
index 0000000000..0375c441af
--- /dev/null
+++ b/lib/ssh/doc/src/book.xml
@@ -0,0 +1,46 @@
+<?xml version="1.0" encoding="latin1" ?>
+<!DOCTYPE book SYSTEM "book.dtd">
+
+<book xmlns:xi="http://www.w3.org/2001/XInclude">
+  <header titlestyle="normal">
+    <copyright>
+      <year>2005</year><year>2009</year>
+      <holder>Ericsson AB. All Rights Reserved.</holder>
+    </copyright>
+    <legalnotice>
+      The contents of this file are subject to the Erlang Public License,
+      Version 1.1, (the "License"); you may not use this file except in
+      compliance with the License. You should have received a copy of the
+      Erlang Public License along with this software. If not, it can be
+      retrieved online at http://www.erlang.org/.
+    
+      Software distributed under the License is distributed on an "AS IS"
+      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+      the License for the specific language governing rights and limitations
+      under the License.
+    
+    </legalnotice>
+
+    <title>SSH</title>
+    <prepared>OTP Team</prepared>
+    <docno></docno>
+    <date>2007-10-06</date>
+    <rev>%VSN%</rev>
+    <file>book.sgml</file>
+  </header>
+  <insidecover>
+  </insidecover>
+  <pagetext>SSH</pagetext>
+  <preamble>
+    <contents level="2"></contents>
+  </preamble>
+  <applications>
+    <xi:include href="ref_man.xml"/>
+  </applications>
+  <releasenotes>
+    <xi:include href="notes.xml"/>
+  </releasenotes>
+  <listofterms></listofterms>
+  <index></index>
+</book>
+
diff --git a/lib/ssh/doc/src/fascicules.xml b/lib/ssh/doc/src/fascicules.xml
new file mode 100644
index 0000000000..43090b4aed
--- /dev/null
+++ b/lib/ssh/doc/src/fascicules.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="latin1" ?>
+<!DOCTYPE fascicules SYSTEM "fascicules.dtd">
+
+<fascicules>
+  <fascicule file="ref_man" href="ref_man_frame.html" entry="yes">
+    Reference Manual
+  </fascicule>
+  <fascicule file="part_notes" href="part_notes_frame.html" entry="no">
+    Release Notes
+  </fascicule>
+  <fascicule file="" href="../../../../doc/print.html" entry="no">
+    Off-Print
+  </fascicule>
+</fascicules>
+
diff --git a/lib/ssh/doc/src/make.dep b/lib/ssh/doc/src/make.dep
new file mode 100644
index 0000000000..cfe2f9617b
--- /dev/null
+++ b/lib/ssh/doc/src/make.dep
@@ -0,0 +1,19 @@
+# ----------------------------------------------------
+# >>>> Do not edit this file <<<<
+# This file was automaticly generated by
+# /home/otp/bin/docdepend
+# ----------------------------------------------------
+
+
+# ----------------------------------------------------
+# TeX files that the DVI file depend on
+# ----------------------------------------------------
+
+book.dvi: book.tex ref_man.tex ssh.tex ssh_channel.tex \
+                ssh_connection.tex ssh_sftp.tex ssh_sftpd.tex
+
+# ----------------------------------------------------
+# Source inlined when transforming from source to LaTeX
+# ----------------------------------------------------
+
+book.tex: ref_man.xml
diff --git a/lib/ssh/doc/src/notes.xml b/lib/ssh/doc/src/notes.xml
new file mode 100644
index 0000000000..54e0cf9059
--- /dev/null
+++ b/lib/ssh/doc/src/notes.xml
@@ -0,0 +1,588 @@
+<?xml version="1.0" encoding="latin1" ?>
+<!DOCTYPE chapter SYSTEM "chapter.dtd">
+
+<chapter>
+  <header>
+    <copyright>
+      <year>2004</year><year>2009</year>
+      <holder>Ericsson AB. All Rights Reserved.</holder>
+    </copyright>
+    <legalnotice>
+      The contents of this file are subject to the Erlang Public License,
+      Version 1.1, (the "License"); you may not use this file except in
+      compliance with the License. You should have received a copy of the
+      Erlang Public License along with this software. If not, it can be
+      retrieved online at http://www.erlang.org/.
+    
+      Software distributed under the License is distributed on an "AS IS"
+      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+      the License for the specific language governing rights and limitations
+      under the License.
+    
+    </legalnotice>
+
+    <title>SSH Release Notes</title>
+    <prepared></prepared>
+    <docno></docno>
+    <date></date>
+    <rev>%VSN%</rev>
+    <file>notes.xml</file>
+  </header>
+
+ <section><title>Ssh 1.1.7</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+            Now clear all processes when a connnection is terminated.</p>
+          <p>
+            Own Id: OTP-8121 Aux Id:</p>
+        </item>
+        <item>
+          <p>
+            In some rare cases the connection handler could enter an infinite loop.</p>
+          <p>
+            Own Id: OTP-8277 Aux Id: seq11428</p>
+        </item>
+        <item>
+          <p>
+            If an SFTP server did not respond with EOF, the function 
+            ssh_sftp:list_dir/2/3 would enter an infinite loop.</p>
+          <p>
+            Own Id: OTP-8278 Aux Id: seq11450</p>
+        </item>
+      </list>
+    </section>
+
+    <section><title>Improvements and New Features</title>
+      <list>
+        <item>
+          <p>
+            The documentation is now built with open source tools (xsltproc and fop) 
+            that exists on most platforms. One visible change is that the frames are removed.</p>
+          <p>
+            Own Id: OTP-8201 Aux Id:</p>
+        </item>
+      </list>
+    </section>
+
+ </section>
+
+ <section><title>Ssh 1.1.6</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+            ssh_sftp:start_channel did not handle all possible return 
+            values from ssh_channel:start correctly.
+          </p>
+          <p>
+            Own Id: OTP-8176 Aux Id: </p>
+        </item>
+        <item>
+          <p>
+            SFTPD did not handle rename command (version 4) correctly.
+          </p>
+          <p>
+            Own Id: OTP-8175 Aux Id: seq11373</p>
+        </item>
+        <item>
+          <p>
+            If a connection manager already had been terminated it could cause a channel
+            to generate a crash report when it was about to stop.
+          </p>
+          <p>
+            Own Id: OTP-8174 Aux Id: seq11377</p>
+        </item>
+        <item>
+          <p>
+            Requests could result in badarg or badmatch EXIT messages in the connection 
+            manager if the channel no longer existed.</p>
+          <p>
+            Own Id: OTP-8173 Aux Id: seq11379</p>
+        </item>
+        <item>
+          <p>
+            ssh_transport:unpack/3 could cause a badarg error.</p>
+          <p>
+            Own Id: OTP-8162 Aux Id:</p>
+        </item>
+      </list>
+    </section>
+
+    <section><title>Improvements and New Features</title>
+      <list>
+        <item>
+          <p>
+            The encryption algorithm aes128-cbc is now supported.
+            Requires that crypto-1.6.1 is available.</p>
+          <p>
+            Own Id: OTP-8110 Aux Id:</p>
+        </item>
+      </list>
+    </section>
+
+ </section>
+
+
+ <section><title>Ssh 1.1.5</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+            ssh_sftp:start_channel/3 did not handle timout correctly.</p>
+          <p>
+            Own Id: OTP-8159 Aux Id: seq11386</p>
+        </item>
+        <item>
+          <p>
+            If a progress message was not recieved after invoking ssh:connect/3
+            the call could hang for ever. A timeout option has also been added.</p>
+          <p>
+            Own Id: OTP-8160 Aux Id: seq11386</p>
+        </item>
+        <item>
+          <p>
+            A comma has been missing in the ssh.appup file since SSH-1.0.2.</p>
+          <p>
+            Own Id: OTP-8161 Aux Id:</p>
+        </item>
+      </list>
+    </section>
+
+ </section>
+
+ <section><title>Ssh 1.1.4</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+            SSH sometimes caused a crash report at disconnect.</p>
+          <p>
+            Own Id: OTP-8071 Aux Id: seq11319</p>
+        </item>
+      </list>
+    </section>
+
+ </section>
+
+ <section><title>Ssh 1.1.3</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+            The operation ssh_sftp:stop_channel/1 returned an 
+            exception if the connection already had been closed.</p>
+          <p>
+            Own Id: OTP-7996 Aux Id: seq11281</p>
+        </item>
+        <item>
+          <p>
+            SSH did not handle if supervisor:start_child/2 returned 
+            {error, already_present}.</p>
+          <p>
+            Own Id: OTP-8034 Aux Id: seq11307</p>
+        </item>
+        <item>
+          <p>
+            SSH no longer cause supervisor reports when a connection is 
+            terminated in a controlled manner.</p>
+          <p>
+            Own Id: OTP-8035 Aux Id: seq11308</p>
+        </item>
+      </list>
+    </section>
+
+ </section>
+
+ <section><title>Ssh 1.1.2</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+            Ssh confused local and remote channel id's, which in some
+            cases resulted in that messages were discarded.</p>
+          <p>
+            Own Id: OTP-7914 Aux Id: seq11234</p>
+        </item>
+        <item>
+          <p>
+            Ssh could not handle echo values other than 0 and 1.</p>
+          <p>
+            Own Id: OTP-7917 Aux Id: seq11238</p>
+        </item>
+        <item>
+          <p>
+            A crash occurred if a non-valid channel reference was received.</p>
+          <p>
+            Own Id: OTP-7918 Aux Id: seq11238</p>
+        </item>
+        <item>
+          <p>
+            Sftpd connections was not closed after receiving eof from a client.</p>
+          <p>
+            Own Id: OTP-7921 Aux Id: seq11222</p>
+        </item>
+        <item>
+          <p>
+            It was not possible to start a SFTP subsystem on certain platforms, 
+            i.e. those who do not support symbolic links.</p>
+          <p>
+            Own Id: OTP-7930 Aux Id: </p>
+        </item>
+        <item>
+          <p>
+            In some cases the message {ssh_cm, ssh_connection_ref(), {closed, ssh_channel_id()}}
+            was not passed to the registered callback module.</p>
+          <p>
+            Own Id: OTP-7957 Aux Id: </p>
+        </item>
+      </list>
+    </section>
+
+    <section><title>Improvements and New Features</title>
+      <list>
+        <item>
+          <p>
+            By using the sftpd option {max_files, Integer}, the message
+            size for READDIR commands can be reduced.</p>
+          <p>
+            Own Id: OTP-7919 Aux Id: seq11230</p>
+        </item>
+      </list>
+    </section>
+
+ </section>
+
+ <section><title>Ssh 1.1.1</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+            The erlang ssh server has presented itself incorrectly,
+            using the special version ssh-1.99, although it never has
+            supported versions below 2.0. Since ssh-1.1 client
+            versions below 2.0 are correctly rejected instead of
+            letting the server crash later on. Alas the problem with
+            the presentation string was not discovered until after
+            ssh.1.1 was released. Now the server will present itself
+            as ssh-2.0.</p>
+          <p>
+            Own Id: OTP-7795</p>
+        </item>
+        <item>
+          <p>
+            An internal function call used an incorrect parameter, which
+            caused problem when the old listen API was used. This was
+            introduced in Ssh-1.1.</p>
+          <p>
+            Own Id: OTP-7920 Aux Id: seq11211</p>
+        </item>
+      </list>
+    </section>
+
+    <section><title>Improvements and New Features</title>
+      <list>
+        <item>
+          <p>
+            Ssh timeouts will now behave as expected e.i. defaults to
+            infinity only the user of the ssh application can know of
+            a reasonable timeout value for their application.</p>
+          <p>
+            *** POTENTIAL INCOMPATIBILITY ***</p>
+          <p>
+            Own Id: OTP-7807</p>
+        </item>
+        <item>
+          <p>
+            The implementation of timeouts added as a patch in
+            ssh-1.0.1 was slightly changed and is now documented.</p>
+          <p>
+            Own Id: OTP-7808</p>
+        </item>
+        <item>
+          <p>
+            To honor the multiplexing of channels over one ssh
+            connection concept ssh_sftp:connect/ [1,2,3] is
+            deprecated and replaced by ssh_sftp:start_channel/[1,2,3]
+            and ssh_sftp:stop/1 is deprecated and replaced by
+            ssh_sftp:stop_channel/1 and to stop the ssh connection
+            ssh:close/ 1 should be called.</p>
+          <p>
+            Own Id: OTP-7809</p>
+        </item>
+        <item>
+          <p>
+            Added the message {ssh_channel_up, ChannelId,
+            ConnectionManager} that shall be handled by the channel
+            callback handle_msg/2. This makes the function
+            handle_msg/2 a mandatory function for ssh channels
+            implementations which it was not in ssh-1.1.</p>
+          <p>
+            *** POTENTIAL INCOMPATIBILITY ***</p>
+          <p>
+            Own Id: OTP-7828</p>
+        </item>
+      </list>
+    </section>
+
+ </section>
+
+  <section><title>Ssh 1.1</title>
+  
+  <section><title>Fixed Bugs and Malfunctions</title>
+  <list>
+    <item>
+      <p>
+	A flaw in the implementation of the supervision tree
+	caused the ssh daemon to close the connections to all
+	currently logged in users if one user logged out. Another
+	problem related to the supervision tree caused the closing
+	down of clients to leak processes e.i. all processes was
+      not shutdown correctly.</p>
+      <p>
+      Own Id: OTP-7676</p>
+    </item>
+    <item>
+      <p>
+	Tabs could cause ssh_cli to print things in a surprising
+      way.</p>
+      <p>
+      Own Id: OTP-7683 Aux Id: seq11102 </p>
+    </item>
+    <item>
+      <p>
+	[sftp, sftpd] - Added patch to make sftp timestamps more
+	correct, in the long run it would be nice to have better
+	support in file to be able to make it always behave
+	correctly now it will be correct 99 % of time instead of
+      almost never correct, at least on unix-based platforms.</p>
+      <p>
+      Own Id: OTP-7685 Aux Id: seq11082 </p>
+    </item>
+    <item>
+      <p>
+	[sftpd] - Added patch to further improve handling of
+      symbolic links in the sftp-server.</p>
+      <p>
+      Own Id: OTP-7766 Aux Id: seq11101 </p>
+    </item>
+    <item>
+      <p>
+	Ssh incorrectly sent the local id instead of the remote
+	id of a channel to the peer. For simpler cases these ids
+	often happen to have the same value. One case when they
+	do not is when the client sends an exec command two times
+	in a raw on the same ssh connection (different channels
+	of course as the channel will be closed when the exec
+      command has been evaluated) .</p>
+      <p>
+      Own Id: OTP-7767</p>
+    </item>
+    <item>
+      <p>
+	Packet data could be lost under high load due to the fact
+	that buffered data was sometimes wrongly discarded before
+      it had been sent.</p>
+      <p>
+      Own Id: OTP-7768</p>
+    </item>
+    <item>
+      <p>
+	Improved ipv6-handling as some assumptions about inet
+      functions where incorrect.</p>
+      <p>
+      Own Id: OTP-7770</p>
+    </item>
+  </list>
+  </section>
+
+  
+  <section><title>Improvements and New Features</title>
+  <list>
+    <item>
+      <p>
+      Added new API function ssh:connection_info/2.</p>
+      <p>
+      Own Id: OTP-7456</p>
+    </item>
+    <item>
+      <p>
+	Now starts ssh channel processes later avoiding
+      synchronization problems between processes.</p>
+      <p>
+      Own Id: OTP-7516</p>
+    </item>
+    <item>
+      <p>
+	Ssh now rejects old versions of the ssh protocol for
+	security reasons. (Even if they where not correctly
+	rejected before the connection would probably have failed
+      anyway due to other reasons.)</p>
+      <p>
+      Own Id: OTP-7645 Aux Id: seq11094 </p>
+    </item>
+    <item>
+      <p>
+	New API module ssh_channel has been added. This is a
+	behaviour to facilitate the implementation of ssh clients
+	and plug in subsystems to the ssh daemon. Note that this
+	slightly changes the options to the API function
+	ssh:daemon/[1,2,3] deprecating all no longer documented
+	options. Note that the new API enforces the "logical way"
+	of using the old API e.i. making the subsystem process
+	part of the ssh applications supervisor tree, so missuses
+      of the old API are not compatible with the new API.</p>
+      <p>
+      *** POTENTIAL INCOMPATIBILITY ***</p>
+      <p>
+      Own Id: OTP-7769</p>
+    </item>
+  </list>
+  </section>
+
+  <section><title>Known Bugs and Problems</title>
+  <list>
+    <item>
+      <p>
+	Public keys protected by a password are currently not
+      handled by the erlang ssh application.</p>
+      <p>
+      Own Id: OTP-6400 Aux Id: 10595 </p>
+    </item>
+  </list>
+  </section>
+  
+  </section>
+    
+    <section><title>Ssh 1.0.2</title>
+    
+    <section><title>Fixed Bugs and Malfunctions</title>
+    <list>
+      <item>
+	<p>
+	  [sftpd] - Listing of symbolic link directories should now
+	  work as expected.</p>
+	  <p>
+	  Own Id: OTP-7141 Aux Id: seq10856 </p>
+        </item>
+    </list>
+    </section>
+    
+    </section>
+    
+   <section><title>Ssh 1.0.1</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+            [sftp] - When listing a directory with more than 100
+            files only the first 100 where listed. This has now been
+            fixed.</p>
+          <p>
+            Own Id: OTP-7318 Aux Id: seq10953 </p>
+        </item>
+        <item>
+          <p>
+            When restarting an ssh-system the expected return value
+            from ssh_system_sup:restart_acceptor/2 was incorrect,
+            this is no longer the case.</p>
+          <p>
+            Own Id: OTP-7564 Aux Id: seq11055 </p>
+        </item>
+        <item>
+          <p>
+            A few minor bugs where fixed in ssh_userreg.erl and
+            ssh_connection_manager and a a ssh_cli option was added
+            to restore backwards compatibility with the old ssh_cm -
+            API.</p>
+          <p>
+            Own Id: OTP-7565</p>
+        </item>
+        <item>
+          <p>
+            Fixed bug in ipv6 support and added option to disable
+            ipv6 as a workaround for badly configured computers.</p>
+          <p>
+            Own Id: OTP-7566</p>
+        </item>
+      </list>
+    </section>
+
+    <section><title>Improvements and New Features</title>
+      <list>
+        <item>
+          <p>
+            [sftp] - Option added to set timeout value in sftp.</p>
+          <p>
+            Own Id: OTP-7305 Aux Id: seq10945 </p>
+        </item>
+      </list>
+    </section>
+
+   </section>
+
+  <section><title>Ssh 1.0</title>
+
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+            Removed some special handling of prompts that made ssh
+            behave differently than openssh.</p>
+          <p>
+            Own Id: OTP-7485 Aux Id: seq11025 </p>
+        </item>
+        <item>
+          <p>
+            Bug in encoding of pty opts has been fixed.</p>
+          <p>
+            Own Id: OTP-7504</p>
+        </item>
+      </list>
+    </section>
+
+
+    <section><title>Improvements and New Features</title>
+      <list>
+        <item>
+          <p>
+            The architecture of the ssh processes has been
+            reconstructed to fit in a supervision tree as to become a
+            real OTP application and benefit from this when starting
+            and stopping.</p>
+          <p>
+            Own Id: OTP-7356 Aux Id: seq10899 </p>
+        </item>
+        <item>
+          <p>
+            Support for pty option echo off added. Requires kernel
+            from R12B-4.</p>
+          <p>
+            *** POTENTIAL INCOMPATIBILITY ***</p>
+          <p>
+            Own Id: OTP-7502 Aux Id: seq10959 </p>
+        </item>
+        <item>
+          <p>
+            The ssh API has been enhanced a lot of old API functions
+            has become deprecated.</p>
+          <p>
+            Own Id: OTP-7503</p>
+        </item>
+      </list>
+    </section>
+
+    <!-- p>For information about older versions see
+      <url href="part_notes_history_frame.html">release notes history</url>.</p -->
+  </section>
+</chapter>
+
diff --git a/lib/ssh/doc/src/notes_history.xml b/lib/ssh/doc/src/notes_history.xml
new file mode 100644
index 0000000000..bfebcd4bf4
--- /dev/null
+++ b/lib/ssh/doc/src/notes_history.xml
@@ -0,0 +1,737 @@
+<?xml version="1.0" encoding="latin1" ?>
+<!DOCTYPE chapter SYSTEM "chapter.dtd">
+
+<chapter>
+  <header>
+    <copyright>
+      <year>2009</year>
+      <year>2009</year>
+      <holder>Ericsson AB, All Rights Reserved</holder>
+    </copyright>
+    <legalnotice>
+  The contents of this file are subject to the Erlang Public License,
+  Version 1.1, (the "License"); you may not use this file except in
+  compliance with the License. You should have received a copy of the
+  Erlang Public License along with this software. If not, it can be
+  retrieved online at http://www.erlang.org/.
+
+  Software distributed under the License is distributed on an "AS IS"
+  basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+  the License for the specific language governing rights and limitations
+  under the License.
+
+  The Initial Developer of the Original Code is Ericsson AB.
+    </legalnotice>
+
+    <title>SSH Release Notes History</title>
+    <prepared></prepared>
+    <responsible></responsible>
+    <docno></docno>
+    <approved></approved>
+    <checked></checked>
+    <date></date>
+    <rev>A</rev>
+    <file>notes_history.xml</file>
+  </header>
+
+  <section><title>Ssh 0.9.9.6</title>
+
+    <section><title>Improvements and New Features</title>
+      <list>
+        <item>
+          <p>
+            Updated asn1 file due to change in the asn1 compiler.
+            This has no semantical effect on the ssh application.</p>
+          <p>
+            Own Id: OTP-7246</p>
+        </item>
+        <item>
+          <p>
+            Allows for the option {fd, FD} in listen and connect
+            calls. The option is passed on to gen_tcp:listen and
+            gen_tcp:connect</p>
+          <p>
+            Own Id: OTP-7247</p>
+        </item>
+      </list>
+    </section>
+</section>
+
+  <section><title>Ssh 0.9.9.5</title>
+    
+    <section><title>Fixed Bugs and Malfunctions</title>
+      <list>
+        <item>
+          <p>
+	    Putty version 0.60 sends ignore messages, which hanged
+	    the OTP ssh server.</p>
+          <p>
+	    Own Id: OTP-7076</p>
+        </item>
+        <item>
+          <p>
+	    ssh_cm hanged when connection was closed during
+	    handshake. (Triggered by putty 0.60 client.)</p>
+          <p>
+	    Own Id: OTP-7089</p>
+        </item>
+        <item>
+          <p>
+	    Fixed crash in server when receiving an empty ignore-msg.
+	    (From the putty 0.60 client.)</p>
+          <p>
+	    Own Id: OTP-7135</p>
+        </item>
+      </list>
+    </section>
+
+
+    <section><title>Improvements and New Features</title>
+      <list>
+        <item>
+          <p>
+	    Now uses the base 64 encode/decode function in stdlib.</p>
+          <p>
+	    Own Id: OTP-6486</p>
+        </item>
+        <item>
+          <p>
+	    Removed runtime dependency on asn1.</p>
+          <p>
+	    Own Id: OTP-6570</p>
+        </item>
+        <item>
+          <p>
+	    Documentation update of ssh.</p>
+          <p>
+	    Own Id: OTP-7063 Aux Id: seq10789 </p>
+        </item>
+        <item>
+          <p>
+	    Same listener is used for both sshd and sftpd. Previously
+	    the sftpd server had to be run on a separate port, now
+	    the sshd listener will start an sftpd server when an sftp
+	    client connects.</p>
+          <p>
+	    Own Id: OTP-7090 Aux Id: seq10675 </p>
+        </item>
+        <item>
+          <p>
+	    Kebord-interactive support, according to rfc 4256, has
+	    been added to the ssh client. Also the option
+	    <c>quiet_mode</c> has been added so that unwanted banners
+	    may be suppressed.</p>
+          <p>
+	    Own Id: OTP-7106 Aux Id: seq10841 </p>
+        </item>
+      </list>
+    </section>
+
+  </section>
+    
+    <section><title>Ssh 0.9.9.4</title>
+    
+    <section><title>Improvements and New Features</title>
+    <list>
+      <item>
+	<p>
+	  [sftpd] - Root parameter now behaves as expected,
+	instead of making sftpd malfunction.</p>
+	<p>
+	Own Id: OTP-7057 Aux Id: seq10830 </p>
+      </item>
+    </list>
+    </section>
+    </section>
+    
+  <section><title>Ssh 0.9.9.3</title>
+  
+  <section><title>Fixed Bugs and Malfunctions</title>
+  <list>
+    <item>
+      <p>
+	The sftp-server could crash if a "ls" was done on the
+	client, and a file was removed while ssh_sftpd:list_dir
+	was reading the directory, an error code from
+	read_file_info wasn't handled properly. This fix makes ls
+      return an error code instead.</p>
+      <p>
+      Own Id: OTP-6854 Aux Id: seq10740 </p>
+    </item>
+    <item>
+      <p>
+	Fixed bugs in prompting in ssl_cli. Prompts like \003>
+	were written as \300>. Also, newlines and returns was
+      removed.</p>
+      <p>
+      Own Id: OTP-6917 Aux Id: seq10773 </p>
+    </item>
+  </list>
+  </section>
+
+    <section><title>Improvements and New Features</title>
+      <list>
+        <item>
+          <p>
+            [sftpd] - New option "root" to set the root of the
+            sftp-server and the callback module for file handling now
+	  has a state parameter.</p>
+	  <p>
+            Own Id: OTP-7075 Aux Id: seq10675 </p>
+	</item>
+      </list>
+    </section>
+  </section>
+  
+    <section>
+    <title>Ssh 0.9.9.2</title>
+    <section>
+      <title>Better error-handling in ssh_sshd:listen</title>
+      <list type="bulleted">
+        <item>
+	  <p>The caller was hanged when listening with ssh_sshd:listen
+		(or ssh_sftpd:listen) on a port and IP already in use.
+		Now an error is returned instead.</p>
+          <p>Own Id: OTP-6727</p>
+        </item>
+      </list>
+    </section>
+
+    <section>
+      <title>Fix in ssh_sftpd</title>
+      <list type="bulleted">
+        <item>
+	  <p>Cd ../.. didn't work when connecting to a ssh_sftpd server.</p>
+          <p>Own Id: OTP-6727</p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>Ssh 0.9.9.1</title>
+
+    <section>
+      <title>Minor Makefile changes</title>
+      <list type="bulleted">
+        <item>
+          <p>Removed use of <c><![CDATA[erl_flags]]></c> from Makefile.</p>
+          <p>Own Id: OTP-6689</p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>Ssh 0.9.9</title>
+
+    <section>
+      <title>Fixed Bugs and Malfunctions</title>
+      <list type="bulleted">
+        <item>
+          <p>A race condition that could make the server crash if a
+            client sent a SSH_MSG_USERAUTH_REQUEST packet immediately
+            after its SSH_MSG_SERVICE_REQUEST, is removed.</p>
+          <p>Own Id: OTP-6379 Aux Id: seq10523 </p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>Ssh 0.9.8</title>
+
+    <section>
+      <title>Fixed Bugs and Malfunctions</title>
+      <list type="bulleted">
+        <item>
+          <p>Corrected minor bugs and removed dead code found by
+            dialyzer.</p>
+          <p>Own Id: OTP-6524</p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>Ssh 0.9.7</title>
+
+    <section>
+      <title>Fixed Bugs and Malfunctions</title>
+      <list type="bulleted">
+        <item>
+          <p>[sftp] - The function ssh_sftp:make_symlink/3 was not
+            fully implemented.</p>
+          <p>Own Id: OTP-6446</p>
+        </item>
+        <item>
+          <p>[ssh] - An internal value was, due to a bug, always set
+            to undefined even when it was not, this could lead to
+            connections being wrongly refused.</p>
+          <p>Own Id: OTP-6450</p>
+        </item>
+        <item>
+          <p>A pattern matching was missing "/binary" resulting in
+            that the internal function ssh_xfer:decode_acl/2 did not
+            work as expected.</p>
+          <p>Own Id: OTP-6458</p>
+        </item>
+        <item>
+          <p>[sftp] - read_link/2 did not return the documented value</p>
+          <p>Own Id: OTP-6471</p>
+        </item>
+        <item>
+          <p>Removed debugg printouts from ssh_cli.erl</p>
+          <p>Own Id: OTP-6483</p>
+        </item>
+        <item>
+          <p>[sftp, ssh] - The connection timeout was overridden by an
+            internal gen_server default timeout.</p>
+          <p>Own Id: OTP-6488 Aux Id: seq10569 </p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>Ssh 0.9.6</title>
+
+    <section>
+      <title>Fixed Bugs and Malfunctions</title>
+      <list type="bulleted">
+        <item>
+          <p>Removed debug printout from production code.</p>
+          <p>Own Id: OTP-6348 Aux Id: seq10510 </p>
+        </item>
+        <item>
+          <p>[sftpd] - When the sftp client ends the session the
+            server will now behave correctly and not leave the client
+            hanging.</p>
+          <p>Own Id: OTP-6349 Aux Id: seq10510 </p>
+        </item>
+        <item>
+          <p>[sftpd] - No longer used files were not closed until the
+            session was ended.</p>
+          <p>Own Id: OTP-6350 Aux Id: seq10514 </p>
+        </item>
+        <item>
+          <p>[sftpd] - File rename requests sent by sftp version 3
+            clients were not handled.</p>
+          <p>Own Id: OTP-6352 Aux Id: seq10513 </p>
+        </item>
+        <item>
+          <p>[sftpd] - Request that did not fit into one ssh message
+            were not handled.</p>
+          <p>Own Id: OTP-6353 Aux Id: seq10515 </p>
+        </item>
+        <item>
+          <p>Removed error logging of auth method none, as this is not
+            an error but rather a feature, that is used to get
+            initial information from the server.</p>
+          <p>Own Id: OTP-6414</p>
+        </item>
+      </list>
+    </section>
+
+    <section>
+      <title>Improvements and New Features</title>
+      <list type="bulleted">
+        <item>
+          <p>[sftpd] - Added new option to specify a callback module
+            for the sftpd-server file handling. The default callback
+            module uses file and filelib.</p>
+          <p>Own Id: OTP-6356 Aux Id: seq10519 </p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>Ssh 0.9.5</title>
+
+    <section>
+      <title>Fixed Bugs and Malfunctions</title>
+      <list type="bulleted">
+        <item>
+          <p>The data window in SSH wasn't resized in the ssh_cli
+            receive data, this made the ssh_cli-server hang if more
+            than 64K data was received at one time. The option
+            tcp_nodelay was added, for nodelay in tcp connections.</p>
+          <p>Own Id: OTP-6231</p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>SSH 0.9.4</title>
+
+    <section>
+      <title>Reported Fixed Bugs and Malfunctions</title>
+      <list type="bulleted">
+        <item>
+          <p>Unnecessary explicit start of crypto application 
+            in ssh application. This has been removed. The 
+            app-file specifies that ssh depends on the crypto app.
+            This is enough. See also the 
+            <seealso marker="ssh">ssh</seealso> module.</p>
+          <p>Also changed some error reports to info reports.</p>
+          <p>Own Id: OTP-6183</p>
+          <p>Aux Id: Seq 10383</p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>SSH 0.9.3</title>
+
+    <section>
+      <title>Improvements and New Features</title>
+      <list type="bulleted">
+        <item>
+          <p>Added way for cli to get peer name</p>
+          <p>Own Id: OTP-6138</p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>SSH 0.9.2</title>
+
+    <section>
+      <title>Improvements and New Features</title>
+      <list type="bulleted">
+        <item>
+          <p>Added some options to listen</p>
+          <p>Own Id: OTP-6070</p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>SSH 0.9.1</title>
+    <section><title>Ssh 0.9.9.4</title>
+    
+    <section><title>Improvements and New Features</title>
+    <list>
+      <item>
+	<p>
+	  [sftpd] - Root parameter now behaves as expected,
+	instead of making sftpd malfunction.</p>
+	<p>
+	Own Id: OTP-7057 Aux Id: seq10830 </p>
+      </item>
+    </list>
+    </section>
+    </section>
+    
+  <section><title>Ssh 0.9.9.3</title>
+  
+  <section><title>Fixed Bugs and Malfunctions</title>
+  <list>
+    <item>
+      <p>
+	The sftp-server could crash if a "ls" was done on the
+	client, and a file was removed while ssh_sftpd:list_dir
+	was reading the directory, an error code from
+	read_file_info wasn't handled properly. This fix makes ls
+      return an error code instead.</p>
+      <p>
+      Own Id: OTP-6854 Aux Id: seq10740 </p>
+    </item>
+    <item>
+      <p>
+	Fixed bugs in prompting in ssl_cli. Prompts like \003>
+	were written as \300>. Also, newlines and returns was
+      removed.</p>
+      <p>
+      Own Id: OTP-6917 Aux Id: seq10773 </p>
+    </item>
+  </list>
+  </section>
+
+    <section><title>Improvements and New Features</title>
+      <list>
+        <item>
+          <p>
+            [sftpd] - New option "root" to set the root of the
+            sftp-server and the callback module for file handling now
+	  has a state parameter.</p>
+	  <p>
+            Own Id: OTP-7075 Aux Id: seq10675 </p>
+	</item>
+      </list>
+    </section>
+  </section>
+  
+    <section>
+    <title>Ssh 0.9.9.2</title>
+    <section>
+      <title>Better error-handling in ssh_sshd:listen</title>
+      <list type="bulleted">
+        <item>
+	  <p>The caller was hanged when listening with ssh_sshd:listen
+		(or ssh_sftpd:listen) on a port and IP already in use.
+		Now an error is returned instead.</p>
+          <p>Own Id: OTP-6727</p>
+        </item>
+      </list>
+    </section>
+
+    <section>
+      <title>Fix in ssh_sftpd</title>
+      <list type="bulleted">
+        <item>
+	  <p>Cd ../.. didn't work when connecting to a ssh_sftpd server.</p>
+          <p>Own Id: OTP-6727</p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>Ssh 0.9.9.1</title>
+
+    <section>
+      <title>Minor Makefile changes</title>
+      <list type="bulleted">
+        <item>
+          <p>Removed use of <c><![CDATA[erl_flags]]></c> from Makefile.</p>
+          <p>Own Id: OTP-6689</p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>Ssh 0.9.9</title>
+
+    <section>
+      <title>Fixed Bugs and Malfunctions</title>
+      <list type="bulleted">
+        <item>
+          <p>A race condition that could make the server crash if a
+            client sent a SSH_MSG_USERAUTH_REQUEST packet immediately
+            after its SSH_MSG_SERVICE_REQUEST, is removed.</p>
+          <p>Own Id: OTP-6379 Aux Id: seq10523 </p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>Ssh 0.9.8</title>
+
+    <section>
+      <title>Fixed Bugs and Malfunctions</title>
+      <list type="bulleted">
+        <item>
+          <p>Corrected minor bugs and removed dead code found by
+            dialyzer.</p>
+          <p>Own Id: OTP-6524</p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>Ssh 0.9.7</title>
+
+    <section>
+      <title>Fixed Bugs and Malfunctions</title>
+      <list type="bulleted">
+        <item>
+          <p>[sftp] - The function ssh_sftp:make_symlink/3 was not
+            fully implemented.</p>
+          <p>Own Id: OTP-6446</p>
+        </item>
+        <item>
+          <p>[ssh] - An internal value was, due to a bug, always set
+            to undefined even when it was not, this could lead to
+            connections being wrongly refused.</p>
+          <p>Own Id: OTP-6450</p>
+        </item>
+        <item>
+          <p>A pattern matching was missing "/binary" resulting in
+            that the internal function ssh_xfer:decode_acl/2 did not
+            work as expected.</p>
+          <p>Own Id: OTP-6458</p>
+        </item>
+        <item>
+          <p>[sftp] - read_link/2 did not return the documented value</p>
+          <p>Own Id: OTP-6471</p>
+        </item>
+        <item>
+          <p>Removed debugg printouts from ssh_cli.erl</p>
+          <p>Own Id: OTP-6483</p>
+        </item>
+        <item>
+          <p>[sftp, ssh] - The connection timeout was overridden by an
+            internal gen_server default timeout.</p>
+          <p>Own Id: OTP-6488 Aux Id: seq10569 </p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>Ssh 0.9.6</title>
+
+    <section>
+      <title>Fixed Bugs and Malfunctions</title>
+      <list type="bulleted">
+        <item>
+          <p>Removed debug printout from production code.</p>
+          <p>Own Id: OTP-6348 Aux Id: seq10510 </p>
+        </item>
+        <item>
+          <p>[sftpd] - When the sftp client ends the session the
+            server will now behave correctly and not leave the client
+            hanging.</p>
+          <p>Own Id: OTP-6349 Aux Id: seq10510 </p>
+        </item>
+        <item>
+          <p>[sftpd] - No longer used files were not closed until the
+            session was ended.</p>
+          <p>Own Id: OTP-6350 Aux Id: seq10514 </p>
+        </item>
+        <item>
+          <p>[sftpd] - File rename requests sent by sftp version 3
+            clients were not handled.</p>
+          <p>Own Id: OTP-6352 Aux Id: seq10513 </p>
+        </item>
+        <item>
+          <p>[sftpd] - Request that did not fit into one ssh message
+            were not handled.</p>
+          <p>Own Id: OTP-6353 Aux Id: seq10515 </p>
+        </item>
+        <item>
+          <p>Removed error logging of auth method none, as this is not
+            an error but rather a feature, that is used to get
+            initial information from the server.</p>
+          <p>Own Id: OTP-6414</p>
+        </item>
+      </list>
+    </section>
+
+    <section>
+      <title>Improvements and New Features</title>
+      <list type="bulleted">
+        <item>
+          <p>[sftpd] - Added new option to specify a callback module
+            for the sftpd-server file handling. The default callback
+            module uses file and filelib.</p>
+          <p>Own Id: OTP-6356 Aux Id: seq10519 </p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>Ssh 0.9.5</title>
+
+    <section>
+      <title>Fixed Bugs and Malfunctions</title>
+      <list type="bulleted">
+        <item>
+          <p>The data window in SSH wasn't resized in the ssh_cli
+            receive data, this made the ssh_cli-server hang if more
+            than 64K data was received at one time. The option
+            tcp_nodelay was added, for nodelay in tcp connections.</p>
+          <p>Own Id: OTP-6231</p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>SSH 0.9.4</title>
+
+    <section>
+      <title>Reported Fixed Bugs and Malfunctions</title>
+      <list type="bulleted">
+        <item>
+          <p>Unnecessary explicit start of crypto application 
+            in ssh application. This has been removed. The 
+            app-file specifies that ssh depends on the crypto app.
+            This is enough. See also the 
+            <seealso marker="ssh">ssh</seealso> module.</p>
+          <p>Also changed some error reports to info reports.</p>
+          <p>Own Id: OTP-6183</p>
+          <p>Aux Id: Seq 10383</p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>SSH 0.9.3</title>
+
+    <section>
+      <title>Improvements and New Features</title>
+      <list type="bulleted">
+        <item>
+          <p>Added way for cli to get peer name</p>
+          <p>Own Id: OTP-6138</p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>SSH 0.9.2</title>
+
+    <section>
+      <title>Improvements and New Features</title>
+      <list type="bulleted">
+        <item>
+          <p>Added some options to listen</p>
+          <p>Own Id: OTP-6070</p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+  <section>
+    <title>SSH 0.9.1</title>
+
+    <section>
+      <title>Improvements and New Features</title>
+      <list type="bulleted">
+        <item>
+          <p>Fixes in ssh_sftp, changes of timeout handling,
+            expand_fun moved to io:setopts</p>
+          <p>Own Id: OTP-5877 Aux Id: OTP-5781 </p>
+        </item>
+      </list>
+    </section>
+  </section>
+
+    <section>
+      <title>SSH 0.9</title>
+      
+      <section>
+	<title>Improvements and New Features</title>
+	<list type="bulleted">
+	  <item>
+          <p>The previously undocumented and UNSUPPORTED <c><![CDATA[ssh]]></c>
+            application has been updated and documented. This release
+	      of the <c><![CDATA[ssh]]></c> application is still considered to be a
+            beta release and (if necessary) there could still be
+	      changes in its API before it reaches 1.0.</p>
+	    <p>Also, more cryptographic algorithms have been added to
+	      the <c><![CDATA[crypto]]></c> application.</p>
+          <p>*** POTENTIAL INCOMPATIBILITY ***</p>
+	    <p>Own Id: OTP-5631</p>
+	  </item>
+	</list>
+      </section>
+    </section>
+  </section>
+
+</chapter>
+
+
diff --git a/lib/ssh/doc/src/part_notes.xml b/lib/ssh/doc/src/part_notes.xml
new file mode 100644
index 0000000000..f87efffe5c
--- /dev/null
+++ b/lib/ssh/doc/src/part_notes.xml
@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="latin1" ?>
+<!DOCTYPE part SYSTEM "part.dtd">
+
+<part xmlns:xi="http://www.w3.org/2001/XInclude">
+  <header>
+    <copyright>
+      <year>2004</year><year>2009</year>
+      <holder>Ericsson AB. All Rights Reserved.</holder>
+    </copyright>
+    <legalnotice>
+      The contents of this file are subject to the Erlang Public License,
+      Version 1.1, (the "License"); you may not use this file except in
+      compliance with the License. You should have received a copy of the
+      Erlang Public License along with this software. If not, it can be
+      retrieved online at http://www.erlang.org/.
+    
+      Software distributed under the License is distributed on an "AS IS"
+      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+      the License for the specific language governing rights and limitations
+      under the License.
+    
+    </legalnotice>
+
+    <title>SSH Release Notes</title>
+    <prepared>Jakob Cederlund</prepared>
+    <docno></docno>
+    <date></date>
+    <rev>%VSN%</rev>
+    <file>part_notes.sgml</file>
+  </header>
+  <description>
+    <p>This document describes the changes made to the SSH application.
+      </p>
+      <p>For information about older versions see
+      <url href="part_notes_history_frame.html">release notes history</url>.</p>  </description>
+  <xi:include file="notes.xml"/>
+</part>
+
diff --git a/lib/ssh/doc/src/part_notes_history.xml b/lib/ssh/doc/src/part_notes_history.xml
new file mode 100644
index 0000000000..49f72fd3db
--- /dev/null
+++ b/lib/ssh/doc/src/part_notes_history.xml
@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="latin1" ?>
+<!DOCTYPE part SYSTEM "part.dtd">
+
+<part>
+  <header>
+    <copyright>
+      <year>2004</year>
+      <year>2007</year>
+      <holder>Ericsson AB, All Rights Reserved</holder>
+    </copyright>
+    <legalnotice>
+  The contents of this file are subject to the Erlang Public License,
+  Version 1.1, (the "License"); you may not use this file except in
+  compliance with the License. You should have received a copy of the
+  Erlang Public License along with this software. If not, it can be
+  retrieved online at http://www.erlang.org/.
+
+  Software distributed under the License is distributed on an "AS IS"
+  basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+  the License for the specific language governing rights and limitations
+  under the License.
+
+  The Initial Developer of the Original Code is Ericsson AB.
+    </legalnotice>
+
+    <title>Ssh</title>
+    <prepared>Ingela Anderton Andin</prepared>
+    <docno></docno>
+    <date></date>
+    <rev></rev>
+    <file>part_notes.xml</file>
+  </header>
+  <include file="notes_history"></include>
+</part>
+
+
diff --git a/lib/ssh/doc/src/ref_man.xml b/lib/ssh/doc/src/ref_man.xml
new file mode 100644
index 0000000000..c05c3051b0
--- /dev/null
+++ b/lib/ssh/doc/src/ref_man.xml
@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="latin1" ?>
+<!DOCTYPE application SYSTEM "application.dtd">
+
+<application xmlns:xi="http://www.w3.org/2001/XInclude">
+  <header>
+    <copyright>
+      <year>2004</year><year>2009</year>
+      <holder>Ericsson AB. All Rights Reserved.</holder>
+    </copyright>
+    <legalnotice>
+      The contents of this file are subject to the Erlang Public License,
+      Version 1.1, (the "License"); you may not use this file except in
+      compliance with the License. You should have received a copy of the
+      Erlang Public License along with this software. If not, it can be
+      retrieved online at http://www.erlang.org/.
+    
+      Software distributed under the License is distributed on an "AS IS"
+      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+      the License for the specific language governing rights and limitations
+      under the License.
+    
+    </legalnotice>
+
+    <title>SSH Reference Manual</title>
+    <prepared>Jakob Cederlund</prepared>
+    <docno></docno>
+    <date>2007-10-06</date>
+    <rev>%VSN%</rev>
+    <file>application.sgml</file>
+  </header>
+  <description>
+    <p>The SSH application is an erlang implementation of the
+      secure shell protocol.</p>
+  </description>
+  <xi:include href="ssh.xml"/>
+  <xi:include href="ssh_channel.xml"/>
+  <xi:include href="ssh_connection.xml"/>
+  <xi:include href="ssh_sftp.xml"/>
+  <xi:include href="ssh_sftpd.xml"/>
+</application>
+
diff --git a/lib/ssh/doc/src/ssh.xml b/lib/ssh/doc/src/ssh.xml
new file mode 100644
index 0000000000..aca5c9cdc4
--- /dev/null
+++ b/lib/ssh/doc/src/ssh.xml
@@ -0,0 +1,337 @@
+<?xml version="1.0" encoding="latin1" ?>
+<!DOCTYPE erlref SYSTEM "erlref.dtd">
+
+<erlref>
+  <header>
+    <copyright>
+      <year>2004</year><year>2009</year>
+      <holder>Ericsson AB. All Rights Reserved.</holder>
+    </copyright>
+    <legalnotice>
+      The contents of this file are subject to the Erlang Public License,
+      Version 1.1, (the "License"); you may not use this file except in
+      compliance with the License. You should have received a copy of the
+      Erlang Public License along with this software. If not, it can be
+      retrieved online at http://www.erlang.org/.
+    
+      Software distributed under the License is distributed on an "AS IS"
+      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+      the License for the specific language governing rights and limitations
+      under the License.
+    
+    </legalnotice>
+    
+    <title>ssh</title>
+    <prepared>Ingela Anderton Andin</prepared>
+    <responsible>H&aring;kan Mattsson</responsible>
+    <docno></docno>
+    <approved>H&aring;kan Mattsson</approved>
+    <checked></checked>
+    <date>2007-10-06</date>
+    <rev>PA1</rev>
+  </header>
+  <module>ssh</module>
+  <modulesummary>Main API of the SSH application</modulesummary>
+  <description>
+    <p>Interface module for the SSH application</p>
+  </description>
+
+  
+  <section>
+    <title>COMMON DATA TYPES </title>
+    <p>Type definitions that are used more than once in
+    this module:</p>
+    <p><c>boolean() = true | false </c></p>
+    <p><c>string() = list of ASCII characters</c></p>
+    <p><c>ssh_daemon_ref() - opaque to the user
+    returned by ssh:daemon/[1,2,3]</c></p>
+    <p><c>ssh_connection_ref() - opaque to the user
+    returned by ssh:connect/3</c></p>
+    <p><c>ip_address() - {N1,N2,N3,N4} % IPv4 |
+    {K1,K2,K3,K4,K5,K6,K7,K8} % IPv6</c></p>
+    <p><c>subsystem_spec() = {subsystem_name(), {channel_callback(), channel_init_args()}} </c></p>  
+    <p><c>subsystem_name() = string() </c></p>
+    <p><c>channel_callback() = atom() - Name of the erlang module
+    implementing the subsystem using the ssh_channel behavior see</c>
+    <seealso marker="ssh_channel">ssh_channel(3)</seealso></p>
+    <p><c>channel_init_args() = list()</c></p>
+ </section>
+  
+ <funcs>
+   
+   <func>
+     <name>close(ConnectionRef) -> ok </name>
+      <fsummary>Closes a ssh connection</fsummary>
+      <type>
+	<v>ConnectionRef = ssh_connection_ref()</v>
+      </type>
+      <desc><p>Closes a ssh connection.</p> 
+      </desc>
+    </func>
+    
+    <func>
+      <name>connect(Host, Port, Options) -> </name>
+      <name>connect(Host, Port, Options, Timeout) -> {ok, ssh_connection_ref()}
+      | {error, Reason}</name>
+      <fsummary>Connect to an ssh server.</fsummary>
+      <type>
+        <v>Host = string()</v>
+	<v>Port = integer()</v>
+	<d>The default is <c><![CDATA[22]]></c>, the registered port for SSH.</d>
+	<v>Options = [{Option, Value}]</v>
+	<v>Timeout = infinity | integer(milliseconds)</v>
+      </type>
+      <desc>
+	<p>Connects to an SSH server. No channel is started this is done
+	by calling ssh_connect:session_channel/2.</p>
+	<p>Options are:</p>
+	<taglist>
+          <tag><c><![CDATA[{user_dir, String}]]></c></tag>
+	  <item>
+	    <p>Sets the user directory e.i. the directory containing
+	    ssh configuration files for the user such as
+	    <c><![CDATA[known_hosts]]></c>, <c><![CDATA[id_rsa, id_dsa]]></c> and
+	    <c><![CDATA[authorized_key]]></c>. Defaults to the directory normally
+	    referred to as <c><![CDATA[~/.ssh]]></c> </p>
+	  </item>
+          <tag><c><![CDATA[{silently_accept_hosts, boolean()}]]></c></tag>
+	  <item>
+	    <p>When true hosts are added to the
+	    file <c><![CDATA[known_hosts]]></c> without asking the user.
+	    Defaults to false.
+	    </p>
+	  </item>
+	  <tag><c><![CDATA[{user_interaction, boolean()}]]></c></tag>
+	  <item>
+	    <p>If false disables the client to connect to the server
+	    if any user interaction is needed such as accepting that
+	    the server will be added to the <c>known_hosts</c> file or
+	    supplying a password. Defaults to true.
+	    Even if user interaction is allowed it can be
+	    suppressed by other options such as silently_accept_hosts and
+	    password. Do note that it may not always be desirable to use
+	    those options from a security point of view.</p>
+	  </item>
+	  <tag><c><![CDATA[{public_key_alg, ssh_rsa | ssh_dsa}]]></c></tag>
+	  <item>
+            <p>Sets the preferred public key algorithm to use for user
+	    authentication. If the the preferred algorithm fails of
+	    some reason, the other algorithm is tried. The  default is
+	    to try <c><![CDATA[ssh_rsa]]></c> first.</p>
+	  </item>
+	  <tag><c><![CDATA[{connect_timeout, timeout()}]]></c></tag>
+	  <item>
+	    <p>Sets a timeout on the transport layer connection. Defaults to infinity.</p>
+	  </item>
+	  <tag><c><![CDATA[{user, String}]]></c></tag>
+          <item>
+	    <p>Provide a user name. If this option is not given, ssh
+	    reads from the environment (<c><![CDATA[LOGNAME]]></c> or
+	    <c><![CDATA[USER]]></c> on unix,
+	    <c><![CDATA[USERNAME]]></c> on Windows).</p>
+          </item>
+	  <tag><c><![CDATA[{password, string()}]]></c></tag>
+          <item>
+	    <p>Provide a password for password authentication.  If
+	    this option is not given, the user will be asked for a
+	    password if the password authentication method is
+	    attempted.</p>
+          </item>
+          <tag><c><![CDATA[{user_auth, Fun/3}]]></c></tag>
+          <item>
+	    <p>Provide a fun for password authentication. The fun
+	    will be called as <c><![CDATA[fun(User, Password, Opts)]]></c> and
+	    should return <c><![CDATA[true]]></c> or <c><![CDATA[false]]></c>.</p>
+	  </item>
+	  <tag><c><![CDATA[{key_cb, atom() = KeyCallbackModule}]]></c></tag>
+	  <item>
+	    <p>Provide a special call-back module for key handling.
+	    The call-back module should be modeled after the
+	    <c><![CDATA[ssh_file]]></c> module. The functions that must
+	    be exported are:
+	    <c><![CDATA[private_host_rsa_key/2]]></c>,
+	    <c><![CDATA[private_host_dsa_key/2]]></c>,
+	    <c><![CDATA[lookup_host_key/3]]></c> and
+	    <c><![CDATA[add_host_key/3]]></c>. This is considered
+	    somewhat experimental and will be better documented later on.</p>
+	  </item>
+	  <tag><c><![CDATA[{fd, file_descriptor()}]]></c></tag>
+	  <item>
+	    <p>Allow an existing file-descriptor to be used
+	  (simply passed on to the transport protocol).</p></item>
+	</taglist>
+      </desc>   
+    </func>
+
+    <func>
+      <name>connection_info(ConnectionRef, [Option]) ->[{Option, Value}] </name>
+      <fsummary> Retrieves information about a connection. </fsummary>
+      <type>
+        <v>Option = client_version | server_version | peer</v>
+	<v>Value = term() </v>
+      </type>
+      <desc>
+        <p> Retrieves information about a connection. 
+	</p>
+      </desc>
+    </func>
+    
+    <func>
+      <name>daemon(Port) -> </name>
+      <name>daemon(Port, Options) -> </name>
+      <name>daemon(HostAddress, Port, Options) -> ssh_daemon_ref()</name>
+      <fsummary>Starts a server listening for SSH connections 
+      on the given port.</fsummary>
+      <type>
+        <v>Port = integer()</v>
+	<v>HostAddress = ip_address() | any</v>
+	<v>Options = [{Option, Value}]</v>
+        <v>Option = atom()</v>
+	<v>Value = term()</v>
+      </type>
+      <desc>
+        <p>Starts a server listening for SSH connections on the given port.</p>
+      
+        <p>Options are:</p>
+        <taglist>
+	  <tag><c><![CDATA[{subsystems, [subsystem_spec()]]]></c></tag>
+	  <item>
+	    Provides specifications for handling of subsystems.  The
+	    "sftp" subsystem-spec can be retrieved by calling
+	    ssh_sftd:subsystem_spec/1. If the subsystems option in not present
+	    the value of <c>[ssh_sftd:subsystem_spec([])]</c> will be used.
+	    It is of course possible to set the option to the empty list
+	    if you do not want the daemon to run any subsystems at all.
+	  </item>
+	  <tag><c><![CDATA[{shell, {Module, Function, Args} | fun(string() = User) - > pid() |
+	  fun(string() = User, ip_address() = PeerAddr) -> pid()}]]></c></tag>
+	  <item>
+	    Defines the read-eval-print loop used when a shell is requested
+	    by the client. Example use the
+	    erlang shell: <c><![CDATA[{shell, start, []}]]></c> which is
+	    the default behavior.
+	  </item>
+	  <tag><c><![CDATA[{ssh_cli,{channel_callback(), channel_init_args()}}]]></c></tag>
+	  <item>
+	    Provide your own cli implementation, e.i. a channel callback
+	    module that implements a shell and command execution. Note
+	    that you may customize the shell read-eval-print loop using the
+	    option <c>shell</c> which is much less work than implementing
+	    your own cli channel.
+	  </item>
+          <tag><c><![CDATA[{system_dir, string()}]]></c></tag>
+          <item>
+            <p>Sets the system directory, containing the host files
+            that identifies the host for ssh. The default is
+            <c><![CDATA[/etc/ssh]]></c>, note that SSH normally
+            requires the host files there to be readable only by
+            root.</p>
+          </item>
+          <tag><c><![CDATA[{user_passwords, [{string() = User, string() = Password}]}]]></c></tag>
+          <item>
+	    <p>Provide passwords for password authentication.They will
+	    be used when someone tries to connect to the server and
+	    public key user authentication fails. The option provides
+	    a list of valid user names and the corresponding password.
+	    </p>
+          </item>
+          <tag><c><![CDATA[{password, string()}]]></c></tag>
+          <item>
+            <p>Provide a global password that will authenticate any
+              user. From a security perspective this option makes
+	      the server very vulnerable.</p>
+	  </item>
+	  <tag><c><![CDATA[{pwdfun, fun/2}]]></c></tag>
+	  <item>
+	    <p>Provide a function for password validation. This is called
+	      with user and password as strings, and should return
+	      <c><![CDATA[true]]></c> if the password is valid and
+	      <c><![CDATA[false]]></c> otherwise.</p>
+	  </item>
+	  <tag><c><![CDATA[{fd, file_descriptor()}]]></c></tag>
+	  <item>
+	    <p>Allow an existing file-descriptor to be used
+	  (simply passed on to the transport protocol).</p></item>
+        </taglist>
+      </desc>
+    </func>
+
+    <func>
+      <name>shell(Host) -> </name>
+      <name>shell(Host, Option) -> </name>
+      <name>shell(Host, Port, Option) -> _</name>
+      <fsummary> </fsummary>
+      <type>
+        <v> Host = string()</v>
+	<v> Port = integer()</v>
+	<v> Options - see ssh:connect/3</v>
+      </type>
+      <desc>
+        <p>Starts an interactive shell to an SSH server on the
+	given <c>Host</c>. The function waits for user input,
+	and will not return until the remote shell is ended (e.g. on
+	exit from the shell).
+	</p>
+      </desc>
+    </func>
+
+    <func>
+      <name>start() -> </name>
+      <name>start(Type) -> ok | {error, Reason}</name>
+      <fsummary>Starts the Ssh application. </fsummary>
+      <type>
+        <v>Type =  permanent | transient | temporary</v>
+	<v>Reason = term() </v>
+      </type>
+      <desc>
+        <p>Starts the Ssh application. Default type
+          is temporary. See also
+          <seealso marker="kernel:application">application(3)</seealso>
+	  Requires that the crypto application has been started.
+	</p>
+      </desc>
+    </func>
+
+    <func>
+      <name>stop() -> ok </name>
+      <fsummary>Stops the Ssh application.</fsummary>
+      <desc>
+        <p>Stops the Ssh application. See also
+          <seealso marker="kernel:application">application(3)</seealso></p>
+      </desc>
+    </func>
+    
+    <func>
+      <name>stop_daemon(DaemonRef) -> </name>
+      <name>stop_daemon(Address, Port) -> ok </name>
+      <fsummary>Stops the listener and all connections started by 
+      the listener.</fsummary>
+      <type>
+	<v>DaemonRef = ssh_daemon_ref()</v>
+	<v>Address = ip_address()</v>
+	<v>Port = integer()</v>
+      </type>
+      <desc>
+	<p>Stops the listener and all connections started by 
+	the listener.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name>stop_listener(DaemonRef) -> </name>
+      <name>stop_listener(Address, Port) -> ok </name>
+      <fsummary>Stops the listener, but leaves existing connections started
+	by the listener up and running.</fsummary>
+      <type>
+	<v>DaemonRef = ssh_daemon_ref()</v>
+        <v>Address = ip_address()</v>
+	<v>Port = integer()</v>
+      </type>
+      <desc>
+	<p>Stops the listener, but leaves existing connections started
+	by the listener up and running.</p>
+      </desc>
+    </func>
+  </funcs>
+  
+</erlref>
diff --git a/lib/ssh/doc/src/ssh_channel.xml b/lib/ssh/doc/src/ssh_channel.xml
new file mode 100644
index 0000000000..c2b7aa94a5
--- /dev/null
+++ b/lib/ssh/doc/src/ssh_channel.xml
@@ -0,0 +1,520 @@
+<?xml version="1.0" encoding="latin1" ?>
+<!DOCTYPE erlref SYSTEM "erlref.dtd">
+
+<erlref>
+  <header>
+    <copyright>
+      <year>2009</year>
+      <year>2009</year>
+      <holder>Ericsson AB, All Rights Reserved</holder>
+    </copyright>
+    <legalnotice>
+      The contents of this file are subject to the Erlang Public License,
+      Version 1.1, (the "License"); you may not use this file except in
+      compliance with the License. You should have received a copy of the
+      Erlang Public License along with this software. If not, it can be
+      retrieved online at http://www.erlang.org/.
+
+      Software distributed under the License is distributed on an "AS IS"
+      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+      the License for the specific language governing rights and limitations
+      under the License.
+
+      The Initial Developer of the Original Code is Ericsson AB.
+    </legalnotice>
+
+    <title>ssh_channel</title>
+    <prepared>Ingela Anderton Andin</prepared>
+    <responsible></responsible>
+    <docno></docno>
+    <approved></approved>
+    <checked></checked>
+    <date></date>
+    <rev></rev>
+  </header>
+  <module>ssh_channel</module>
+  <modulesummary>Generic Ssh Channel Behavior
+  </modulesummary>
+  <description>
+    <p>Ssh services are implemented as channels that are multiplexed
+    over an ssh connection and communicates via the ssh connection
+    protocol.  This module provides a callback API that takes care of
+    generic channel aspects such as flow control and close messages
+    and lets the callback functions take care of the service specific
+    parts.
+    </p>
+  </description>
+
+  <section>
+    <title>COMMON DATA TYPES </title>
+
+    <p>Type definitions that are used more than once in this module
+    and/or abstractions to indicate the intended use of the data
+    type:</p>
+    
+    <p><c>boolean() = true | false </c></p>
+    <p><c>string() = list of ASCII characters</c></p>
+    <p><c>timeout() =  infinity | integer() - in milliseconds.</c></p>
+    <p><c>ssh_connection_ref() - opaque to the user returned by
+    ssh:connect/3 or sent to a ssh channel process</c></p>
+    <p><c>ssh_channel_id() = integer() </c></p>
+    <p><c>ssh_data_type_code() = 1 ("stderr") | 0 ("normal") are
+    currently valid values see RFC 4254 section 5.2.</c></p>
+  </section>
+
+  <funcs>
+    <func>
+      <name>call(ChannelRef, Msg) -></name>
+      <name>call(ChannelRef, Msg, Timeout) -> Reply | {error, Reason}</name>
+      <fsummary> Makes a synchronous call to a channel.</fsummary>
+      <type>
+	<v>ChannelRef = pid() </v>
+	<d>As returned by start_link/4 </d>
+	<v>Msg = term() </v>
+	<v>Timeout = timeout() </v>
+	<v>Reply = term() </v>
+	<v>Reason = closed | timeout </v>
+      </type>
+      <desc>
+	<p>Makes a synchronous call to the channel process by sending
+	a message and waiting until a reply arrives or a timeout
+	occurs. The channel will call
+	<c>CallbackModule:handle_call/3</c> to handle the message.
+	If the channel process does not exist <c>{error, closed}</c> is returned.
+	</p>
+      </desc>
+    </func>
+    
+    <func>
+      <name>cast(ChannelRef, Msg) -> ok </name>
+      <fsummary>Sends an asynchronous message to the channel
+	ChannelRef and returns ok.</fsummary>
+      <type>
+	<v>ChannelRef = pid() </v>
+	<d>As returned by start_link/4 </d>
+	<v>Msg = term() </v>
+      </type>
+      <desc>
+	<p>Sends an asynchronous message to the channel process and
+	returns ok immediately, ignoring if the destination node or
+	channel process does not exist. The channel will call
+	<c>CallbackModule:handle_cast/2</c> to handle the message.
+	</p>
+      </desc>
+    </func>
+
+       <func>
+      <name>enter_loop(State) -> _ </name>
+      <fsummary> Makes an existing process into a ssh_channel process. </fsummary>
+      <type>
+	<v> State = term() - as returned by  ssh_channel:init/1</v>
+      </type>
+      <desc>
+	<p> Makes an existing process into a <c>ssh_channel</c>
+	process. Does not return, instead the calling process will
+	enter the <c>ssh_channel</c> process receive loop and become a
+	<c>ssh_channel process.</c> The process must have been started using
+	one of the start functions in proc_lib, see <seealso
+	marker="stdlib:proc_lib">proc_lib(3)</seealso>. The
+	user is responsible for any initialization of the process
+	and needs to call ssh_channel:init/1.
+	</p>
+      </desc>
+    </func>
+    
+    <func>
+      <name>init(Options) -> {ok, State} |  {ok, State, Timeout} | {stop, Reason} </name>
+      <fsummary> Initiates a ssh_channel process.</fsummary>
+      <type>
+	<v> Options = [{Option, Value}]</v>
+      </type>
+      <desc>
+	<p>
+	  The following options must be present:
+	</p>
+	  <taglist>
+	  <tag><c><![CDATA[{channel_cb, atom()}]]></c></tag>
+	  <item>The module that implements the channel behavior.</item>
+	  
+	  <tag><c><![CDATA[{init_args(), list()}]]></c></tag>
+	  <item> The list of arguments to the callback modules
+	  init function.</item>
+
+	  <tag><c><![CDATA[{cm, connection_ref()}]]></c></tag>
+	  <item> Reference to the ssh connection.</item>
+	  
+	  <tag><c><![CDATA[{channel_id, channel_id()}]]></c></tag>
+	  <item> Id of the ssh channel.</item>
+	  
+	  </taglist>
+
+	  <note><p>This function is normally not called by the user, it is
+	  only needed if for some reason the channel process needs
+	  to be started with help of <c>proc_lib</c> instead calling
+	  <c>ssh_channel:start/4</c> or <c>ssh_channel:start_link/4</c> </p>
+	  </note>
+      </desc>
+    </func>
+
+    <func>
+      <name>reply(Client, Reply) -> _</name>
+      <fsummary>Send a reply to a client.</fsummary>
+      <type>
+        <v>Client - opaque to the user, see explanation below</v>
+        <v>Reply = term()</v>
+      </type>
+      <desc>
+        <p>This function can be used by a channel to explicitly send a
+        reply to a client that called <c>call/[2,3]</c> when the reply
+        cannot be defined in the return value of
+        <c>CallbackModule:handle_call/3</c>.</p>
+        <p><c>Client</c> must be the <c>From</c> argument provided to
+          the callback function <c>handle_call/3</c>.
+	  <c>Reply</c> is an arbitrary term,
+          which will be given back to the client as the return value of
+          <c>ssh_channel:call/[2,3].</c></p>
+      </desc>
+    </func>
+    
+    <func>
+      <name>start(SshConnection, ChannelId, ChannelCb, CbInitArgs) -> </name>
+      <name>start_link(SshConnection, ChannelId, ChannelCb, CbInitArgs) ->
+      {ok, ChannelRef} | {error, Reason}</name>
+      <fsummary> Starts a processes that handles a ssh channel. </fsummary>
+      <type>
+	<v>SshConnection = ssh_connection_ref()</v>
+	<v>ChannelId = ssh_channel_id() </v>
+	<d> As returned by ssh_connection:session_channel/[2,4]</d>
+	<v>ChannelCb = atom()</v>
+	<d> The name of the module implementing the service specific parts
+	of the channel.</d>
+	<v>CbInitArgs = [term()]</v>
+	<d>Argument  list for the init function in the callback module. </d>
+	<v>ChannelRef = pid()</v>
+      </type>
+      <desc>
+	<p>Starts a processes that handles a ssh channel. Will be
+	called internally by the ssh daemon or explicitly by the ssh
+	client implementations. A channel process traps exit signals
+	by default.
+	</p>
+      </desc>
+    </func>
+    
+  </funcs>
+  
+  <section>
+    <title>CALLBACK FUNCTIONS</title>
+    
+    <p>The functions init/1, terminate/2, handle_ssh_msg/2 and
+    handle_msg/2 are the functions that are required to provide the
+    implementation for a server side channel, such as a ssh subsystem
+    channel that can be plugged into the erlang ssh daemon see
+    <seealso marker="ssh">ssh:daemon/[2, 3]</seealso>. The
+    handle_call/3, handle_cast/2 code_change/3 and enter_loop/1
+    functions are only relevant when implementing a client side
+    channel.</p>
+  </section>
+ 
+  <section>
+    <marker id="cb_timeouts"></marker>
+    <title> CALLBACK TIMEOUTS</title>
+    <p> If an integer timeout value is provided in a return value of
+    one of the callback functions, a timeout will occur unless a
+    message is received within <c>Timeout</c> milliseconds. A timeout
+    is represented by the atom <c>timeout</c> which should be handled
+    by the <seealso marker="#handle_msg">handle_msg/2</seealso>
+    callback function. The atom infinity can be used to wait
+    indefinitely, this is the default value. </p>
+  </section>
+
+  <funcs>
+    <func>
+      <name>CallbackModule:code_change(OldVsn, State, Extra) -> {ok,
+      NewState}</name>
+      <fsummary> Converts process state when code is changed.</fsummary>
+      <type>
+	<v> Converts process state when code is changed.</v>
+      </type>
+      <desc>
+	  <p>This function is called by a client side channel when it
+	  should update its internal state during a release
+	  upgrade/downgrade, i.e. when the instruction
+	  <c>{update,Module,Change,...}</c> where
+	  <c>Change={advanced,Extra}</c> is given in the <c>appup</c>
+	  file. See <seealso
+	  marker="doc/design_principles:release_handling#instr">OTP
+	  Design Principles</seealso> for more information. Any new
+	  connection will benefit from a server side upgrade but
+	  already started connections on the server side will not be
+	  affected.
+	  </p>
+
+	  <note><p>If there are long lived ssh connections and more
+	  than one upgrade in a short time this may cause the old
+	  connections to fail as only two versions of the code may
+	  be loaded simultaneously.</p></note>
+	  
+        <p>In the case of an upgrade, <c>OldVsn</c> is <c>Vsn</c>, and
+          in the case of a downgrade, <c>OldVsn</c> is
+          <c>{down,Vsn}</c>. <c>Vsn</c> is defined by the <c>vsn</c>
+          attribute(s) of the old version of the callback module
+          <c>Module</c>. If no such attribute is defined, the version
+          is the checksum of the BEAM file.</p>
+        <p><c>State</c> is the internal state of the channel.</p>
+        <p><c>Extra</c> is passed as-is from the <c>{advanced,Extra}</c>
+          part of the update instruction.</p>
+        <p>The function should return the updated internal state.</p>
+      </desc>
+    </func>
+    
+    <func>
+      <name>CallbackModule:init(Args) -> {ok, State} | {ok, State, Timeout} |
+      {stop, Reason}</name>
+      <fsummary> Makes necessary initializations and returns the
+      initial channel state if the initializations succeed.</fsummary>
+      <type>
+	<v> Args = term() </v>
+	<d> Last argument to ssh_channel:start_link/4.</d>
+	<v> State = term() </v>
+	<v>Timeout = timeout() </v>
+	<v> Reason = term() </v>
+      </type>
+      <desc>
+	<p> Makes necessary initializations and returns the initial channel
+	state if the initializations succeed.
+	</p>
+	<p>For more detailed information on timeouts see the section 
+	<seealso marker="#cb_timeouts">CALLBACK TIMEOUTS</seealso>. </p>
+      </desc>
+    </func>
+   
+    <func>
+      <name>CallbackModule:handle_call(Msg, From, State) -> Result</name>
+      <fsummary> Handles messages sent by calling
+      <c>ssh_channel:call/[2,3]</c></fsummary>
+      <type>
+	<v>Msg = term()</v>
+	<v>From = opaque to the user should be used as argument to
+	ssh_channel:reply/2</v>
+	<v>State = term()</v>
+	<v>Result = {reply, Reply, NewState} | {reply, Reply, NewState, Timeout}
+	| {noreply, NewState} | {noreply , NewState, Timeout}
+	| {stop, Reason, Reply, NewState} | {stop, Reason, NewState} </v>
+	<v>Reply = term() - will be the return value of ssh_channel:call/[2,3]</v>
+	<v>Timeout = timeout() </v>
+	<v>NewState = term() - a possible updated version of State</v>
+	<v>Reason = term()</v>
+      </type>
+      <desc>
+	<p>Handles messages sent by calling
+	<c>ssh_channel:call/[2,3]</c>	
+	</p>
+	<p>For more detailed information on timeouts see the section 
+	<seealso marker="#cb_timeouts">CALLBACK TIMEOUTS</seealso>. </p>
+      </desc>
+    </func>
+
+    <func>
+      <name>CallbackModule:handle_cast(Msg, State) -> Result</name>
+      <fsummary> Handles messages sent by calling
+      <c>ssh_channel:cact/2</c></fsummary>
+      <type>
+	<v>Msg = term()</v>
+	<v>State = term()</v>
+	<v>Result = {noreply, NewState} | {noreply, NewState, Timeout}
+	| {stop, Reason, NewState}</v>
+	<v>NewState = term() - a possible updated version of State</v>
+	<v>Timeout = timeout() </v>
+	<v>Reason = term()</v>
+      </type>
+      <desc>
+	<p> Handles messages sent by calling
+	<c>ssh_channel:cast/2</c>
+	</p>
+	<p>For more detailed information on timeouts see the section 
+	<seealso marker="#cb_timeouts">CALLBACK TIMEOUTS</seealso>. </p>
+	<marker id="handle_msg"></marker>
+      </desc>
+    </func>
+ 
+    <func>
+      <name>CallbackModule:handle_msg(Msg, State) -> {ok, State} |
+      {stop, ChannelId, State}</name>
+
+      <fsummary> Handle other messages than ssh connection protocol,
+      call or cast messages sent to the channel.</fsummary>
+      <type>
+	<v>Msg = timeout | term()</v>
+	<v>State = term() </v>
+      </type>
+      <desc>
+	<p>Handle other messages than ssh connection protocol, call or
+	cast messages sent to the channel. 
+	</p>
+
+	<p> Possible erlang 'EXIT'-messages should be handled by this
+	function and all channels should handle the following message.</p>
+	
+	<taglist>
+	  <tag><c><![CDATA[{ssh_channel_up, ssh_channel_id(), 
+	  ssh_connection_ref()}]]></c></tag>
+	  <item>This is the first messages that will be received
+	  by the channel, it is sent just before
+	  the ssh_channel:init/1 function returns successfully.
+	  This is especially useful if the server wants
+	  to send a message to the client without first receiving
+	  a message from the client. If the message is not useful
+	  for your particular problem just ignore it by immediately
+	  returning {ok, State}.
+	  </item>
+	</taglist>
+      </desc>
+    </func>
+
+    <func>
+      <name>CallbackModule:handle_ssh_msg(Msg, State) -> {ok, State} | {stop,
+      ssh_channel_id(), State}</name>
+      <fsummary> Handles ssh connection protocol messages. </fsummary>
+      <type>
+	<v>Msg = {ssh_cm, ssh_connection_ref(), SshMsg}</v>
+	<v> SshMsg = tuple() - see message list below</v>
+	<v>State = term()</v>
+      </type>
+      <desc>
+	<p> Handles ssh connection protocol messages that may need
+	service specific attention.
+	</p>
+
+	<p> All channels should handle the following messages.  For
+	channels implementing subsystems the handle_ssh_msg-callback
+	will not be called for any other messages. </p>
+	
+	<taglist>
+	  <tag><c><![CDATA[{ssh_cm, ssh_connection_ref(), {data, ssh_channel_id(),
+	  ssh_data_type_code(), binary() = Data}}]]></c></tag>
+	  <item> Data has arrived on the channel.  When the callback
+	  for this message returns the channel behavior will adjust
+	  the ssh flow control window.</item>
+	  
+	  <tag><c><![CDATA[{ssh_cm, ssh_connection_ref(), {eof,
+	  ssh_channel_id()}}]]></c></tag>
+	  <item>Indicteas that the other side will not send any more
+	  data.</item>
+	  
+	  <tag><c><![CDATA[{ssh_cm, ssh_connection_ref(), {signal,
+	  ssh_channel_id(), ssh_signal()}} ]]></c></tag>
+	  <item>A signal can be delivered to the remote
+	  process/service using the following message.  Some systems
+	  may not implement signals, in which case they should ignore
+	  this message.</item>
+	  
+	  <tag><c><![CDATA[{ssh_cm, ssh_connection_ref(),
+	  {exit_signal, ssh_channel_id(), string() = exit_signal,
+	  string() = ErrorMsg, string() =
+	  LanguageString}}]]></c></tag>
+	  <item>A remote execution may terminate violently due to a
+	  signal then this message may be received. For details on valid string
+	  values see RFC 4254 section 6.10</item>
+	  
+	  <tag><c><![CDATA[{ssh_cm,  ssh_connection_ref(), {exit_status,
+	  ssh_channel_id(), integer() = ExitStatus}}]]></c></tag>
+	  <item> When the command running at the other end terminates,
+	  the following message can be sent to return the exit status
+	  of the command. A zero 'exit_status' usually means that the
+	  command terminated successfully.</item>
+	</taglist>
+
+	<p> Channels implementing a shell and command execution on the server side
+	should also handle the following messages. </p>
+	
+	<taglist>
+	  <tag><c><![CDATA[{ssh_cm, ssh_connection_ref(), {env, ssh_channel_id(),
+	  boolean() = WantReply, string() = Var, string() = Value}}]]></c></tag>
+	  <item> Environment variables may be passed to the
+	  shell/command to be started later. Note that before the
+	  callback returns it should call the function
+	  ssh_connection:reply_request/4 with the boolean value of <c>
+	  WantReply</c> as the second argument.
+	  </item>
+	  
+	  <tag><c><![CDATA[{ssh_cm, ConnectionRef, {exec, ssh_channel_id(),
+	  boolean() = WantReply, string() = Cmd}}]]></c></tag>
+	  <item> This message will request that the server start the
+	  execution of the given command. Note that before the
+	  callback returns it should call the function
+	  ssh_connection:reply_request/4 with the boolean value of <c>
+	  WantReply</c> as the second argument.</item>
+	  
+	  <tag><c><![CDATA[{ssh_cm, ssh_connection_ref(), {pty, ssh_channel_id(),
+	  boolean() = WantReply, {string() = Terminal, integer() = CharWidth,
+	  integer() = RowHeight, integer() = PixelWidth, integer() = PixelHight,
+	  [{atom() | integer() = Opcode,
+	  integer() = Value}] = TerminalModes}}}]]></c></tag>
+	  <item>A pseudo-terminal has been requested for the
+	  session. Terminal is the value of the TERM environment
+	  variable value (e.g., vt100). Zero dimension parameters must
+	  be ignored.  The character/row dimensions override the pixel
+	  dimensions (when nonzero).  Pixel dimensions refer to the
+	  drawable area of the window. The <c>Opcode</c> in the
+	  <c>TerminalModes</c> list is the mnemonic name, represented
+	  as an lowercase erlang atom, defined in RFC 4254 section 8,
+	  or the opcode if the mnemonic name is not listed in the
+	  RFC. Example <c>OP code: 53, mnemonic name ECHO erlang atom:
+	  echo</c>. Note that before the callback returns it should
+	  call the function ssh_connection:reply_request/4 with the
+	  boolean value of <c> WantReply</c> as the second
+	  argument.</item>
+	  
+	  <tag><c><![CDATA[{ssh_cm, ConnectionRef, {shell, boolean() =
+	  WantReply}}]]></c></tag>
+	  <item> This message will request that the user's default
+	  shell be started at the other end.  Note that before the
+	  callback returns it should call the function
+	  ssh_connection:reply_request/4 with the value of <c>
+	  WantReply</c> as the second argument.
+	  </item>
+
+	  <tag><c><![CDATA[ {ssh_cm, ssh_connection_ref(), {window_change,
+	  ssh_channel_id(), integer() = CharWidth, integer() = RowHeight,
+	  integer() = PixWidth, integer() = PixHeight}}]]></c></tag>
+	  <item> When the window (terminal) size changes on the client
+	  side, it MAY send a message to the other side to inform it
+	  of the new dimensions.</item>
+	</taglist>
+	
+	<p> The following message is completely taken care of by the
+	ssh channel behavior</p>
+	
+	<taglist>
+	  <tag><c><![CDATA[{ssh_cm, ssh_connection_ref(), {closed,
+	  ssh_channel_id()}}]]></c></tag>
+	  <item> The channel behavior will send a close message to the
+	  other side if such a message has not already been sent and
+	  then terminate the channel with reason normal.</item>
+	</taglist>
+      </desc>
+    </func>
+
+    <func>
+      <name>CallbackModule:terminate(Reason, State) -> _</name>
+      <fsummary> </fsummary>
+      <type>
+	<v>Reason = term()</v>
+	<v>State = term()</v>
+      </type>
+      <desc>
+	<p>This function is called by a channel process when it is
+	about to terminate. Before this function is called ssh_connection:close/2
+	will be called if it has not been called earlier.
+	This function should be the opposite of <c>CallbackModule:init/1</c>
+	and do any necessary cleaning up. When it returns, the
+	channel process terminates with reason <c>Reason</c>. The return value is
+	ignored.
+	</p>
+      </desc>
+    </func>
+    
+  </funcs>
+  
+</erlref>
diff --git a/lib/ssh/doc/src/ssh_connection.xml b/lib/ssh/doc/src/ssh_connection.xml
new file mode 100644
index 0000000000..499cbbeabe
--- /dev/null
+++ b/lib/ssh/doc/src/ssh_connection.xml
@@ -0,0 +1,302 @@
+<?xml version="1.0" encoding="latin1" ?>
+<!DOCTYPE erlref SYSTEM "erlref.dtd">
+
+<erlref>
+  <header>
+    <copyright>
+      <year>2008</year>
+      <year>2008</year>
+      <holder>Ericsson AB, All Rights Reserved</holder>
+    </copyright>
+    <legalnotice>
+  The contents of this file are subject to the Erlang Public License,
+  Version 1.1, (the "License"); you may not use this file except in
+  compliance with the License. You should have received a copy of the
+  Erlang Public License along with this software. If not, it can be
+  retrieved online at http://www.erlang.org/.
+
+  Software distributed under the License is distributed on an "AS IS"
+  basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+  the License for the specific language governing rights and limitations
+  under the License.
+
+  The Initial Developer of the Original Code is Ericsson AB.
+    </legalnotice>
+
+    <title>ssh_connection</title>
+    <prepared>Ingela Anderton Andin</prepared>
+    <responsible></responsible>
+    <docno></docno>
+    <approved></approved>
+    <checked></checked>
+    <date></date>
+    <rev></rev>
+  </header>
+  <module>ssh_connection</module>
+  <modulesummary>This module provides an API to the ssh connection protocol.
+  </modulesummary>
+  <description>
+    <p>This module provides an API to the ssh connection protocol.
+    Not all features of the connection protocol are officially supported yet.
+    Only the ones supported are documented here.</p>
+  </description>
+
+   <section>
+    <title>COMMON DATA TYPES </title>
+    <p>Type definitions that are used more than once in this module and/or
+    abstractions to indicate the intended use of the data type:</p>
+    
+    <p><c>boolean() = true | false </c></p>
+    <p><c>string() = list of ASCII characters</c></p>
+    <p><c>timeout() =  infinity | integer() - in milliseconds.</c></p>
+    <p><c>ssh_connection_ref() - opaque to the user returned by
+    ssh:connect/3 or sent to a ssh channel processes</c></p>
+    <p><c>ssh_channel_id() = integer() </c></p>
+    <p><c>ssh_data_type_code() = 1 ("stderr") | 0 ("normal") are
+    currently valid values see RFC 4254 section 5.2.</c></p>
+    <p><c>ssh_request_status() = success | failure</c></p>
+   </section>
+
+   <section>
+     <title>MESSAGES SENT TO CHANNEL PROCESSES</title>
+     
+     <p>As a result of the ssh connection protocol messages on the form
+     <c><![CDATA[{ssh_cm, ssh_connection_ref(), term()}]]></c>
+     will be sent to a channel process. The term will contain
+     information regarding the ssh connection protocol event,
+     for details see the ssh channel behavior callback <seealso
+     marker="ssh_channel">handle_ssh_msg/2 </seealso> </p>
+   </section>
+   
+ <funcs>
+   
+   <func>
+     <name>adjust_window(ConnectionRef, ChannelId, NumOfBytes) -> ok</name>
+     <fsummary>Adjusts the ssh flowcontrol window. </fsummary>
+     <type>
+       <v> ConnectionRef = ssh_connection_ref() </v>
+       <v> ChannelId = ssh_channel_id() </v>
+       <v> NumOfBytes = integer()</v>
+     </type>
+      <desc>
+	<p>Adjusts the ssh flowcontrol window. </p>
+	
+	<note><p>This will be taken care of by the ssh_channel
+	behavior when the callback <seealso marker="ssh_channel">
+	handle_ssh_msg/2 </seealso> has returned after processing a
+	{ssh_cm, ssh_connection_ref(), {data, ssh_channel_id(),
+	ssh_data_type_code(), binary()}}
+	message, and should normally not be called explicitly.</p></note>
+      </desc>
+   </func>
+   
+   <func>
+     <name>close(ConnectionRef, ChannelId) -> ok</name>
+     <fsummary>Sends a close message on the channel <c>ChannelId</c>. </fsummary>
+     <type>
+       <v> ConnectionRef = ssh_connection_ref() </v>
+       <v> ChannelId = ssh_channel_id()</v>
+     </type>
+     <desc>
+       <p>Sends a close message on the channel <c>ChannelId</c>
+       </p>
+
+       <note><p>This function will be called by the ssh channel
+       behavior when the channel is terminated see <seealso
+       marker="ssh_channel"> ssh_channel(3) </seealso> and should
+       normally not be called explicitly.</p></note>
+     </desc>
+   </func>
+   
+   <func>
+     <name>exec(ConnectionRef, ChannelId, Command, TimeOut) -> ssh_request_status()  </name>
+     <fsummary>Will request that the server start the
+     execution of the given command.  </fsummary>
+     <type>
+       <v> ConnectionRef = ssh_connection_ref() </v>
+       <v> ChannelId = ssh_channel_id()</v>
+       <v> Command = string()</v>
+       <v>Timeout = timeout() </v>
+     </type>
+     <desc>
+       <p>Will request that the server start the execution of the
+       given command, the result will be received as:</p>
+
+       <taglist>
+	 <tag><c> N X {ssh_cm,
+	 ssh_connection_ref(), {data, ssh_channel_id(), ssh_data_type_code(),
+	 binary() = Data}} </c></tag>
+	 <item>The result of executing the command may be only one line
+	 or thousands of lines depending on the command.</item>
+
+	 <tag><c> 1 X {ssh_cm, ssh_connection_ref(), {eof, ssh_channel_id()}}</c></tag>
+	 <item>Indicates that no more data will be sent.</item>
+
+	 <tag><c>0 or 1 X {ssh_cm,
+	 ssh_connection_ref(), {exit_signal,
+	 ssh_channel_id(), string() = ExitSignal, string() = ErrorMsg, string() = LanguageString}}</c></tag>
+	 <item>Not all systems send signals. For details on valid string
+	 values see RFC 4254 section 6.10 </item>
+	 
+	  <tag><c>0 or 1 X {ssh_cm, ssh_connection_ref(), {exit_status,
+	  ssh_channel_id(), integer() = ExitStatus}}</c></tag>
+	  <item>It is recommended by the <c>ssh connection protocol</c> that this
+	  message shall be sent, but that may not always be the case.</item>
+
+	  <tag><c> 1 X {ssh_cm, ssh_connection_ref(),
+	  {closed, ssh_channel_id()}}</c></tag>
+	  <item>Indicates that the ssh channel started for the
+	  execution of the command has now been shutdown.</item>
+       </taglist>
+       
+       <p> These message should be handled by the
+       client. The <seealso marker="ssh_channel">ssh channel
+       behavior</seealso> can be used when writing a client.
+       </p>
+     </desc>
+   </func>
+
+
+   <func>
+     <name>exit_status(ConnectionRef, ChannelId, Status) -> ok</name>
+     <fsummary>Sends the exit status of a command to the client.</fsummary>
+     <type>
+       <v> ConnectionRef = ssh_connection_ref() </v>
+       <v> ChannelId = ssh_channel_id()</v>
+       <v> Status = integer()</v>
+     </type>
+     <desc>
+       <p>Sends the exit status of a command to the client.</p>
+     </desc>
+ </func>
+   
+     <func>
+       <name>reply_request(ConnectionRef, WantReply, Status, CannelId) -> ok</name>
+       <fsummary>Send status replies to requests that want such replies. </fsummary>
+      <type>
+	<v> ConnectionRef = ssh_connection_ref() </v>
+	<v> WantReply =  boolean()</v>
+	<v> Status = ssh_request_status() </v>
+	<v> ChannelId = ssh_channel_id()</v>
+      </type>
+      <desc>
+	<p>Sends status replies to requests where the requester has
+	stated that they want a status report e.i .<c> WantReply = true</c>,
+	if <c> WantReply</c> is false calling this function will be a
+	"noop". Should be called after handling an ssh connection
+	protocol message containing a <c>WantReply</c> boolean
+	value. See the ssh_channel behavior callback <seealso
+	marker="ssh_channel"> handle_ssh_msg/2 </seealso>
+	</p>
+      </desc>
+     </func>
+    
+     <func>
+       <name>send(ConnectionRef, ChannelId, Data) -></name>
+       <name>send(ConnectionRef, ChannelId, Data, Timeout) -></name>
+       <name>send(ConnectionRef, ChannelId, Type, Data) -></name>
+       <name>send(ConnectionRef, ChannelId, Type, Data, TimeOut) ->
+       ok | {error, timeout}</name>
+       <fsummary>Sends channel data </fsummary>
+       <type>
+	<v> ConnectionRef = ssh_connection_ref() </v>
+	<v> ChannelId = ssh_channel_id()</v>
+	<v> Data = binary()</v>
+	<v> Type = ssh_data_type_code()</v>
+	<v> Timeout = timeout()</v>
+       </type>
+       <desc>
+	 <p>Sends channel data. 
+	 </p>
+       </desc>
+     </func>
+     
+     <func>
+       <name>send_eof(ConnectionRef, ChannelId) -> ok </name>
+       <fsummary>Sends eof on the channel <c>ChannelId</c>.  </fsummary>
+       <type>
+	<v> ConnectionRef = ssh_connection_ref() </v>
+	<v> ChannelId = ssh_channel_id()</v>
+       </type>
+       <desc>
+	 <p>Sends eof on the channel <c>ChannelId</c>.
+	 </p>
+       </desc>
+     </func>
+
+     <func>
+       <name>session_channel(ConnectionRef, Timeout) -> </name>
+       <name>session_channel(ConnectionRef, InitialWindowSize,
+       MaxPacketSize, Timeout) -> {ok, ssh_channel_id()} | {error, Reason}</name>
+       <fsummary>Opens a channel for a ssh session. A session is a
+       remote execution of a program. The program may be a shell, an
+       application, a system command, or some built-in subsystem. </fsummary>
+       <type>
+	 <v> ConnectionRef = ssh_connection_ref()</v>
+	 <v> InitialWindowSize = integer() </v>
+	 <v> MaxPacketSize = integer() </v>
+	 <v> Timeout = timeout()</v>
+	 <v> Reason = term() </v>
+       </type>
+       <desc>
+	 <p>Opens a channel for a ssh session. A session is a
+	 remote execution of a program. The program may be a shell, an
+	 application, a system command, or some built-in subsystem.
+	</p>
+       </desc>
+     </func>
+
+    <func>
+      <name>setenv(ConnectionRef, ChannelId, Var, Value, TimeOut) -> ssh_request_status()</name>
+      <fsummary> Environment variables may be passed to the
+      shell/command to be started later.</fsummary>
+      <type>
+	<v> ConnectionRef = ssh_connection_ref() </v>
+	<v> ChannelId = ssh_channel_id()</v>
+	<v> Var = string()</v>
+	<v> Value = string()</v>
+	<v> Timeout = timeout()</v>
+      </type>
+      <desc>
+	<p> Environment variables may be passed to the shell/command to be
+	started later.
+	</p>
+      </desc>
+    </func>
+    
+    <func>
+      <name>shell(ConnectionRef, ChannelId) -> ssh_request_status()
+      </name>
+      <fsummary> Will request that the user's default shell (typically
+      defined in /etc/passwd in UNIX systems) be started at the other
+      end. </fsummary>
+       <type>
+	 <v> ConnectionRef = ssh_connection_ref() </v>
+	 <v> ChannelId = ssh_channel_id()</v>
+       </type>
+       <desc>
+	 <p> Will request that the user's default shell (typically
+	 defined in /etc/passwd in UNIX systems) be started at the
+	 other end. 
+	 </p>
+       </desc>
+    </func>
+
+    <func>
+      <name>subsystem(ConnectionRef, ChannelId, Subsystem, Timeout) -> ssh_request_status()</name>
+      <fsummary>  </fsummary>
+       <type>
+	 <v> ConnectionRef = ssh_connection_ref() </v>
+	 <v> ChannelId = ssh_channel_id()</v>
+	 <v> Subsystem = string()</v>
+	 <v> Timeout = timeout()</v>
+       </type>
+       <desc>
+	 <p> Sends a request to execute a predefined subsystem.
+	 </p>
+       </desc>
+    </func>
+    
+  </funcs>
+  
+</erlref>
diff --git a/lib/ssh/doc/src/ssh_sftp.xml b/lib/ssh/doc/src/ssh_sftp.xml
new file mode 100644
index 0000000000..208b2b4e72
--- /dev/null
+++ b/lib/ssh/doc/src/ssh_sftp.xml
@@ -0,0 +1,501 @@
+<?xml version="1.0" encoding="latin1" ?>
+<!DOCTYPE erlref SYSTEM "erlref.dtd">
+
+<erlref>
+  <header>
+    <copyright>
+      <year>2005</year><year>2009</year>
+      <holder>Ericsson AB. All Rights Reserved.</holder>
+    </copyright>
+    <legalnotice>
+      The contents of this file are subject to the Erlang Public License,
+      Version 1.1, (the "License"); you may not use this file except in
+      compliance with the License. You should have received a copy of the
+      Erlang Public License along with this software. If not, it can be
+      retrieved online at http://www.erlang.org/.
+    
+      Software distributed under the License is distributed on an "AS IS"
+      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+      the License for the specific language governing rights and limitations
+      under the License.
+    
+    </legalnotice>
+
+    <title>ssh_sftp</title>
+    <prepared>Jakob Cederlund</prepared>
+    <responsible></responsible>
+    <docno>1</docno>
+    <approved></approved>
+    <checked></checked>
+    <date>2005-09-22</date>
+    <rev>PA1</rev>
+    <file>ssh_sftp.sgml</file>
+  </header>
+  <module>ssh_sftp</module>
+  <modulesummary>SFTP client.</modulesummary>
+  <description>
+    <p>This module implements an SFTP (SSH FTP) client. SFTP is a
+      secure, encrypted file transfer service available for
+      SSH.</p>
+  </description>
+  
+ <section>
+    <title>COMMON DATA TYPES </title>
+    <p>Type definitions that are used more than once in this module
+    and/or abstractions to indicate the intended use of the data type:
+    </p>
+    <p><c>ssh_connection_ref() - opaque to the user
+    returned by ssh:connect/3</c></p>
+    <p><c>timeout() =  infinity | integer() - in milliseconds.</c></p>    
+   </section>
+
+ <section>
+    <title>TIMEOUTS </title>
+    <p>If the request functions for the sftp channel return {error, timeout}
+    it does not mean that the request did not reach the server and was
+    not performed, it only means that we did not receive an answer from the
+    server within the time that was expected.</p>
+   </section>
+
+  <funcs>
+    <func>
+      <name>start_channel(ConnectionRef) -> </name>
+      <name>start_channel(ConnectionRef, Options) -> </name>
+      <name>start_channel(Host, Options) -></name>
+      <name>start_channel(Host, Port, Options) -> {ok, Pid} | {ok, Pid, ConnectionRef} |
+      {error, Reason}</name>
+      <fsummary>Starts a sftp client</fsummary>
+      <type>
+        <v>Host = string()</v>
+        <v>ConnectionRef = ssh_connection_ref()</v>
+        <v>Port = integer()</v>
+        <v>Options = [{Option, Value}]</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+	<p>If not provided, setups a ssh connection in this case a
+	connection reference will be returned too. A ssh channel
+	process is started to handle the communication with the SFTP
+	server, the returned pid for this process should be used as
+	input to all other API functions in this module.</p>
+
+	<p>Options are:</p>
+	<taglist>
+          <tag><c><![CDATA[{timeout, timeout()}]]></c></tag>
+	  <item>
+	    <p>The timeout is passed to the ssh_channel start function,
+	    and defaults to infinity.</p>
+	  </item>
+	</taglist>
+	<p>All other options are  directly passed to
+	<seealso marker="ssh">ssh:connect/3</seealso> or ignored if a
+	connection is already provided. </p>
+      </desc>
+    </func>
+
+    <func>
+      <name>stop_channel(ChannelPid) -> ok</name>
+      <fsummary>Stops the sftp client channel.</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+      </type>
+      <desc>
+	<p>Stops a sftp channel. If the ssh connection should be closed
+	call <seealso marker="ssh">ssh:close/1</seealso>.</p>
+      </desc>
+    </func>
+  
+    <func>
+      <name>read_file(ChannelPid, File) -> </name>
+      <name>read_file(ChannelPid, File, Timeout) -> {ok, Data} | {error, Reason}</name>
+      <fsummary>Read a file</fsummary>
+      <type>
+	<v>ChannelPid = pid()</v>
+	<v>File = string()</v>
+        <v>Data = binary()</v>
+	<v>Timeout = timeout()</v>
+	<v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Reads a file from the server, and returns the data in a binary,
+          like <c><![CDATA[file:read_file/1]]></c>.</p>
+      </desc>
+    </func>
+    <func>
+      <name>write_file(ChannelPid, File, Iolist) -> </name>
+      <name>write_file(ChannelPid, File, Iolist, Timeout) -> ok | {error, Reason}</name>
+      <fsummary>Write a file</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>File = string()</v>
+        <v>Iolist = iolist()</v>
+	<v>Timeout = timeout()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Writes a file to the server, like <c><![CDATA[file:write_file/2]]></c>.
+          The file is created if it's not there.</p>
+      </desc>
+    </func>
+    <func>
+      <name>list_dir(ChannelPid, Path) -> </name>
+      <name>list_dir(ChannelPid, Path, Timeout) -> {ok, Filenames} | {error, Reason}</name>
+      <fsummary>List directory</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>Path = string()</v>
+        <v>Filenames = [Filename]</v>
+        <v>Filename = string()</v>
+	<v>Timeout = timeout()</v>
+	<v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Lists the given directory on the server, returning the
+          filenames as a list of strings.</p>
+      </desc>
+    </func>
+    <func>
+      <name>open(ChannelPid, File, Mode) -> </name>
+      <name>open(ChannelPid, File, Mode, Timeout) -> {ok, Handle} | {error, Reason}</name>
+      <fsummary>Open a file and return a handle</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>File = string()</v>
+        <v>Mode = [Modeflag]</v>
+        <v>Modeflag = read | write | creat | trunc | append | binary</v>
+	<v>Timeout = timeout()</v>
+	<v>Handle = term()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Opens a file on the server, and returns a handle that
+          is used for reading or writing.</p>
+      </desc>
+    </func>
+    <func>
+      <name>opendir(ChannelPid, Path) -> </name>
+      <name>opendir(ChannelPid, Path, Timeout) -> {ok, Handle} | {error, Reason}</name>
+      <fsummary>Open a directory and return a handle</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>Path = string()</v>
+	<v>Timeout = timeout()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Opens a handle to a directory on the server, the handle
+          is used for reading directory contents.</p>
+      </desc>
+    </func>
+    <func>
+      <name>close(ChannelPid, Handle) -> </name>
+      <name>close(ChannelPid, Handle, Timeout) -> ok | {error, Reason}</name>
+      <fsummary>Close an open handle</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>Handle = term()</v>
+	<v>Timeout = timeout()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Closes a handle to an open file or directory on the server.</p>
+      </desc>
+    </func>
+    <func>
+      <name>read(ChannelPid, Handle, Len) -> </name>
+      <name>read(ChannelPid, Handle, Len, Timeout) -> {ok, Data} | eof | {error, Error}</name>
+      <name>pread(ChannelPid, Handle, Position, Len) -> </name>
+      <name>pread(ChannelPid, Handle, Position, Len, Timeout) -> {ok, Data} | eof | {error, Error}</name>
+      <fsummary>Read from an open file</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>Handle = term()</v>
+        <v>Position = integer()</v>
+        <v>Len = integer()</v>
+	<v>Timeout = timeout()</v>
+        <v>Data = string() | binary()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Reads <c><![CDATA[Len]]></c> bytes from the file referenced by
+          <c><![CDATA[Handle]]></c>. Returns <c><![CDATA[{ok, Data}]]></c>, or <c><![CDATA[eof]]></c>, or
+          <c><![CDATA[{error, Reason}]]></c>. If the file is opened with <c><![CDATA[binary]]></c>,
+          <c><![CDATA[Data]]></c> is a binary, otherwise it is a string.</p>
+        <p>If the file is read past eof, only the remaining bytes
+          will be read and returned. If no bytes are read, <c><![CDATA[eof]]></c>
+          is returned.</p>
+        <p>The <c><![CDATA[pread]]></c> function reads from a specified position,
+          combining the <c><![CDATA[position]]></c> and <c><![CDATA[read]]></c> functions.</p>
+      </desc>
+    </func>
+    <func>
+      <name>aread(ChannelPid, Handle, Len) -> {async, N} | {error, Error}</name>
+      <name>apread(ChannelPid, Handle, Position, Len) -> {async, N} | {error, Error}</name>
+      <fsummary>Read asynchronously from an open file</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>Handle = term()</v>
+        <v>Position = integer()</v>
+        <v>Len = integer()</v>
+        <v>N = term()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Reads from an open file, without waiting for the result. If the
+          handle is valid, the function returns <c><![CDATA[{async, N}]]></c>, where N
+          is a term guaranteed to be unique between calls of <c><![CDATA[aread]]></c>. 
+          The actual data is sent as a message to the calling process. This
+          message has the form <c><![CDATA[{async_reply, N, Result}]]></c>, where
+          <c><![CDATA[Result]]></c> is the result from the read, either <c><![CDATA[{ok, Data}]]></c>,
+          or <c><![CDATA[eof]]></c>, or <c><![CDATA[{error, Error}]]></c>.</p>
+        <p>The <c><![CDATA[apread]]></c> function reads from a specified position,
+          combining the <c><![CDATA[position]]></c> and <c><![CDATA[aread]]></c> functions.</p>
+      </desc>
+    </func>
+    <func>
+      <name>write(ChannelPid, Handle, Data) -></name>
+      <name>write(ChannelPid, Handle, Data, Timeout) -> ok | {error, Error}</name>
+      <name>pwrite(ChannelPid, Handle, Position, Data) -> ok </name>
+      <name>pwrite(ChannelPid, Handle, Position, Data, Timeout) -> ok | {error, Error}</name>
+      <fsummary>Write to an open file</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>Handle = term()</v>
+        <v>Position = integer()</v>
+        <v>Data = iolist()</v>
+	<v>Timeout = timeout()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Write <c><![CDATA[data]]></c> to the file referenced by <c><![CDATA[Handle]]></c>.
+          The file should be opened with <c><![CDATA[write]]></c> or <c><![CDATA[append]]></c>
+          flag. Returns <c><![CDATA[ok]]></c> if successful and <c><![CDATA[{error, Reason}]]></c>
+          otherwise.</p>
+        <p>Typical error reasons are:</p>
+        <taglist>
+          <tag><c><![CDATA[ebadf]]></c></tag>
+          <item>
+            <p>The file is not opened for writing.</p>
+          </item>
+          <tag><c><![CDATA[enospc]]></c></tag>
+          <item>
+            <p>There is a no space left on the device.</p>
+          </item>
+        </taglist>
+      </desc>
+    </func>
+    <func>
+      <name>awrite(ChannelPid, Handle, Data) -> ok | {error, Reason} </name>
+      <name>apwrite(ChannelPid, Handle, Position, Data) -> ok | {error, Reason}</name>
+      <fsummary>Write asynchronously to an open file</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>Handle = term()</v>
+        <v>Position = integer()</v>
+        <v>Len = integer()</v>
+        <v>Data = binary()</v>
+	<v>Timeout = timeout()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Writes to an open file, without waiting for the result. If the
+          handle is valid, the function returns <c><![CDATA[{async, N}]]></c>, where N
+          is a term guaranteed to be unique between calls of
+          <c><![CDATA[awrite]]></c>. The result of the <c><![CDATA[write]]></c> operation is sent
+          as a message to the calling process. This message has the form
+          <c><![CDATA[{async_reply, N, Result}]]></c>, where <c><![CDATA[Result]]></c> is the result
+          from the write, either <c><![CDATA[ok]]></c>, or <c><![CDATA[{error, Error}]]></c>.</p>
+        <p>The <c><![CDATA[apwrite]]></c> writes on a specified position, combining
+          the <c><![CDATA[position]]></c> and <c><![CDATA[awrite]]></c> operations.</p>
+      </desc>
+    </func>
+    <func>
+      <name>position(ChannelPid, Handle, Location) -> </name>
+      <name>position(ChannelPid, Handle, Location, Timeout) -> {ok, NewPosition | {error, Error}</name>
+      <fsummary>Seek position in open file</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>Handle = term()</v>
+        <v>Location = Offset | {bof, Offset} | {cur, Offset} | {eof, Offset} | bof | cur | eof</v>
+        <v>Offset = int()</v>
+	<v>Timeout = timeout()</v>
+        <v>NewPosition = integer()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Sets the file position of the file referenced by <c><![CDATA[Handle]]></c>.
+          Returns <c><![CDATA[{ok, NewPosition]]></c> (as an absolute offset) if
+          successful, otherwise <c><![CDATA[{error, Reason}]]></c>. <c><![CDATA[Location]]></c> is
+          one of the following:</p>
+        <taglist>
+          <tag><c><![CDATA[Offset]]></c></tag>
+          <item>
+            <p>The same as <c><![CDATA[{bof, Offset}]]></c>.</p>
+          </item>
+          <tag><c><![CDATA[{bof, Offset}]]></c></tag>
+          <item>
+            <p>Absolute offset.</p>
+          </item>
+          <tag><c><![CDATA[{cur, Offset}]]></c></tag>
+          <item>
+            <p>Offset from the current position.</p>
+          </item>
+          <tag><c><![CDATA[{eof, Offset}]]></c></tag>
+          <item>
+            <p>Offset from the end of file.</p>
+          </item>
+          <tag><c><![CDATA[bof | cur | eof]]></c></tag>
+          <item>
+            <p>The same as above with <c><![CDATA[Offset]]></c> 0.</p>
+          </item>
+        </taglist>
+      </desc>
+    </func>
+    <func>
+      <name>read_file_info(ChannelPid, Name) -> </name>
+      <name>read_file_info(ChannelPid, Name, Timeout) -> {ok, FileInfo} | {error, Reason}</name>
+      <fsummary>Get information about a file</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>Name = string()</v>
+        <v>Handle = term()</v>
+	<v>Timeout = timeout()</v>
+        <v>FileInfo = record()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Returns a <c><![CDATA[file_info]]></c> record from the file specified by
+          <c><![CDATA[Name]]></c> or <c><![CDATA[Handle]]></c>, like <c><![CDATA[file:read_file_info/2]]></c>.</p>
+      </desc>
+    </func>
+    <func>
+      <name>read_link_info(ChannelPid, Name) -> {ok, FileInfo} | {error, Reason}</name>
+      <name>read_link_info(ChannelPid, Name, Timeout) -> {ok, FileInfo} | {error, Reason}</name>
+      <fsummary>Get information about a symbolic link</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>Name = string()</v>
+        <v>Handle = term()</v>
+	<v>Timeout = timeout()</v>
+        <v>FileInfo = record()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Returns a <c><![CDATA[file_info]]></c> record from the symbolic
+          link specified by <c><![CDATA[Name]]></c> or <c><![CDATA[Handle]]></c>, like
+          <c><![CDATA[file:read_link_info/2]]></c>.</p>
+      </desc>
+    </func>
+    <func>
+      <name>write_file_info(ChannelPid, Name, Info) -> </name>
+      <name>write_file_info(ChannelPid, Name, Info, Timeout) -> ok | {error, Reason}</name>
+      <fsummary>Write information for a file</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>Name = string()</v>
+        <v>Info = record()</v>
+	<v>Timeout = timeout()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Writes file information from a <c><![CDATA[file_info]]></c> record to the
+          file specified by <c><![CDATA[Name]]></c>, like <c><![CDATA[file:write_file_info]]></c>.</p>
+      </desc>
+    </func>
+    <func>
+      <name>read_link(ChannelPid, Name) -> </name>
+      <name>read_link(ChannelPid, Name, Timeout) -> {ok, Target} | {error, Reason}</name>
+      <fsummary>Read symbolic link</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>Name = string()</v>
+        <v>Target = string()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Read the link target from the symbolic link specified
+          by <c><![CDATA[name]]></c>, like <c><![CDATA[file:read_link/1]]></c>.</p>
+      </desc>
+    </func>
+    <func>
+      <name>make_symlink(ChannelPid, Name, Target) -> </name>
+      <name>make_symlink(ChannelPid, Name, Target, Timeout) -> ok | {error, Reason}</name>
+      <fsummary>Create symbolic link</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>Name = string()</v>
+        <v>Target = string()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Creates a symbolic link pointing to <c><![CDATA[Target]]></c> with the
+          name <c><![CDATA[Name]]></c>, like <c><![CDATA[file:make_symlink/2]]></c>.</p>
+      </desc>
+    </func>
+    <func>
+      <name>rename(ChannelPid, OldName, NewName) ->  </name>
+      <name>rename(ChannelPid, OldName, NewName, Timeout) -> ok | {error, Reason}</name>
+      <fsummary>Rename a file</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>OldName = string()</v>
+        <v>NewName = string()</v>
+	<v>Timeout = timeout()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Renames a file named <c><![CDATA[OldName]]></c>, and gives it the name
+          <c><![CDATA[NewName]]></c>, like <c><![CDATA[file:rename/2]]></c></p>
+      </desc>
+    </func>
+    <func>
+      <name>delete(ChannelPid, Name) -> </name>
+      <name>delete(ChannelPid, Name, Timeout) -> ok | {error, Reason}</name>
+      <fsummary>Delete a file</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>Name = string()</v>
+	<v>Timeout = timeout()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Deletes the file specified by <c><![CDATA[Name]]></c>, like
+          <c><![CDATA[file:delete/1]]></c></p>
+      </desc>
+    </func>
+    <func>
+      <name>make_dir(ChannelPid, Name) -> </name>
+      <name>make_dir(ChannelPid, Name, Timeout) -> ok | {error, Reason}</name>
+      <fsummary>Create a directory</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>Name = string()</v>
+	<v>Timeout = timeout()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Creates a directory specified by <c><![CDATA[Name]]></c>. <c><![CDATA[Name]]></c> should
+          be a full path to a new directory. The directory can only be
+          created in an existing directory.</p>
+      </desc>
+    </func>
+    <func>
+      <name>del_dir(ChannelPid, Name) -> </name>
+      <name>del_dir(ChannelPid, Name, Timeout) -> ok | {error, Reason}</name>
+      <fsummary>Delete an empty directory</fsummary>
+      <type>
+        <v>ChannelPid = pid()</v>
+        <v>Name = string()</v>
+	<v>Timeout = timeout()</v>
+        <v>Reason = term()</v>
+      </type>
+      <desc>
+        <p>Deletes a directory specified by <c><![CDATA[Name]]></c>. The directory
+          should be empty.</p>
+      </desc>
+    </func>
+  
+  </funcs>
+   
+</erlref>
+
diff --git a/lib/ssh/doc/src/ssh_sftpd.xml b/lib/ssh/doc/src/ssh_sftpd.xml
new file mode 100644
index 0000000000..c857983565
--- /dev/null
+++ b/lib/ssh/doc/src/ssh_sftpd.xml
@@ -0,0 +1,94 @@
+<?xml version="1.0" encoding="latin1" ?>
+<!DOCTYPE erlref SYSTEM "erlref.dtd">
+
+<erlref>
+  <header>
+    <copyright>
+      <year>2005</year><year>2009</year>
+      <holder>Ericsson AB. All Rights Reserved.</holder>
+    </copyright>
+    <legalnotice>
+      The contents of this file are subject to the Erlang Public License,
+      Version 1.1, (the "License"); you may not use this file except in
+      compliance with the License. You should have received a copy of the
+      Erlang Public License along with this software. If not, it can be
+      retrieved online at http://www.erlang.org/.
+    
+      Software distributed under the License is distributed on an "AS IS"
+      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+      the License for the specific language governing rights and limitations
+      under the License.
+    
+    </legalnotice>
+
+    <title>ssh_sftpd</title>
+    <prepared>Ingela Anderton Andin</prepared>
+    <responsible></responsible>
+    <docno>1</docno>
+    <approved></approved>
+    <checked></checked>
+    <date>2005-09-22</date>
+    <rev>PA1</rev>
+    <file>ssh_sftpd.sgml</file>
+  </header>
+  <module>ssh_sftpd</module>
+  <modulesummary>Specifies a channel process to handle a sftp subsystem.</modulesummary>
+  <description>
+    <p>Specifies a channel process to handle a sftp subsystem.</p>
+  </description>
+
+  <section>
+    <title>COMMON DATA TYPES </title>
+    <p><c>subsystem_spec() = {subsystem_name(), {channel_callback(), channel_init_args()}} </c></p>
+    <p><c>subsystem_name() =  "sftp"</c></p>
+    <p><c>channel_callback() = atom()</c> - Name of the erlang module implementing the
+    subsystem using the ssh_channel behavior see
+    <seealso marker="ssh_channel">ssh_channel(3)</seealso></p>
+    <p><c> channel_init_args() = list() - The one given as argument to function
+    subsystem_spec/1.</c></p>  
+  </section>
+  <funcs>
+    <func>
+      <name>subsystem_spec(Options) -> subsystem_spec()</name>
+      <fsummary>Returns the subsystem specification that allows an ssh daemon to handle the subsystem "sftp".</fsummary>
+      <type>
+	<v>Options = [{Option, Value}]</v>
+      </type>
+      <desc>
+        <p>Should be used together with ssh:daemon/[1,2,3]</p>
+        <p>Options are:</p>
+        <taglist>
+          <tag><c><![CDATA[{cwd, String}]]></c></tag>
+          <item>
+            <p>Sets the initial current working directory for the
+              server.</p>
+          </item>
+          <tag><c><![CDATA[{file_handler, CallbackModule}]]></c></tag>
+          <item>
+            <p>Determines which module to call for communicating with
+              the file server. Default value is <c>ssh_sftpd_file</c> that uses the
+              file and filelib API:s to access the standard OTP file
+              server. This option may be used to plug in the use of
+              other file servers.</p>
+          </item>
+          <tag><c><![CDATA[{max_files, Integer}]]></c></tag>
+          <item>
+            <p>The default value is <c>0</c>, which means that there is no upper limit.
+               If supplied, the number of filenames returned to the sftp client per <c>READDIR</c>
+               request, is limited to at most the given value.</p>
+          </item>
+	  <tag><c><![CDATA[{root, String}]]></c></tag>
+	  <item>
+	    <p>Sets the sftp root directory. The user will then not be
+	      able to see any files above this root. If for instance
+	      the root is set to <c>/tmp</c> the user will see this
+	      directory as <c>/</c> and if the user does cd <c>/etc</c>
+	      the user will end up in <c>/tmp/etc</c>.
+	    </p>
+	  </item>
+        </taglist>
+      </desc>
+    </func>
+  </funcs>  
+</erlref>
+
diff --git a/lib/ssh/doc/src/user_guide.gif b/lib/ssh/doc/src/user_guide.gif
new file mode 100644
index 0000000000..e6275a803d
--- /dev/null
+++ b/lib/ssh/doc/src/user_guide.gif
diff --git a/lib/ssh/doc/standard/draft-ietf-secsh-architecture-15.2.ps b/lib/ssh/doc/standard/draft-ietf-secsh-architecture-15.2.ps
new file mode 100644
index 0000000000..d766a933b4
--- /dev/null
+++ b/lib/ssh/doc/standard/draft-ietf-secsh-architecture-15.2.ps
@@ -0,0 +1,3315 @@
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+(Network Working Group                                          T. Ylonen) s
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+(Expires: March 31, 2004                                   D. Moffat, Ed.) s
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+(                                                   Sun Microsystems, Inc) s
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+(                                                                Oct 2003) s
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+(                       SSH Protocol Architecture) s
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+(                  draft-ietf-secsh-architecture-15.txt) s
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+(Status of this Memo) s
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+(   This document is an Internet-Draft and is in full conformance with) s
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+(   all provisions of Section 10 of RFC2026.) s
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+(   Internet-Drafts are working documents of the Internet Engineering) s
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+(   groups may also distribute working documents as Internet-Drafts.) s
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+(   Internet-Drafts are draft documents valid for a maximum of six months) s
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+(   and may be updated, replaced, or obsoleted by other documents at any) s
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+(   time. It is inappropriate to use Internet-Drafts as reference) s
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+(   material or to cite them other than as "work in progress.") s
+5 437 M
+(   The list of current Internet-Drafts can be accessed at http://) s
+5 426 M
+(   www.ietf.org/ietf/1id-abstracts.txt.) s
+5 404 M
+(   The list of Internet-Draft Shadow Directories can be accessed at) s
+5 393 M
+(   http://www.ietf.org/shadow.html.) s
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+(   This Internet-Draft will expire on March 31, 2004.) s
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+(Copyright Notice) s
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+(   Copyright \(C\) The Internet Society \(2003\). All Rights Reserved.) s
+5 305 M
+(Abstract) s
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+(   SSH is a protocol for secure remote login and other secure network) s
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+(   services over an insecure network. This document describes the) s
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+(   architecture of the SSH protocol, as well as the notation and) s
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+(   terminology used in SSH protocol documents. It also discusses the SSH) s
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+(   algorithm naming system that allows local extensions. The SSH) s
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+(   protocol consists of three major components: The Transport Layer) s
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+(   Protocol provides server authentication, confidentiality, and) s
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+(   integrity with perfect forward secrecy. The User Authentication) s
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+(   Protocol authenticates the client to the server. The Connection) s
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+(   Protocol multiplexes the encrypted tunnel into several logical) s
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+(   channels. Details of these protocols are described in separate) s
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+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
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+(   documents.) s
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+(Table of Contents) s
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+(   1.    Contributors . . . . . . . . . . . . . . . . . . . . . . . .  3) s
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+(   2.    Introduction . . . . . . . . . . . . . . . . . . . . . . . .  3) s
+5 624 M
+(   3.    Specification of Requirements  . . . . . . . . . . . . . . .  3) s
+5 613 M
+(   4.    Architecture . . . . . . . . . . . . . . . . . . . . . . . .  3) s
+5 602 M
+(   4.1   Host Keys  . . . . . . . . . . . . . . . . . . . . . . . . .  4) s
+5 591 M
+(   4.2   Extensibility  . . . . . . . . . . . . . . . . . . . . . . .  5) s
+5 580 M
+(   4.3   Policy Issues  . . . . . . . . . . . . . . . . . . . . . . .  5) s
+5 569 M
+(   4.4   Security Properties  . . . . . . . . . . . . . . . . . . . .  6) s
+5 558 M
+(   4.5   Packet Size and Overhead . . . . . . . . . . . . . . . . . .  6) s
+5 547 M
+(   4.6   Localization and Character Set Support . . . . . . . . . . .  7) s
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+(   5.    Data Type Representations Used in the SSH Protocols  . . . .  8) s
+5 525 M
+(   6.    Algorithm Naming . . . . . . . . . . . . . . . . . . . . . . 10) s
+5 514 M
+(   7.    Message Numbers  . . . . . . . . . . . . . . . . . . . . . . 11) s
+5 503 M
+(   8.    IANA Considerations  . . . . . . . . . . . . . . . . . . . . 11) s
+5 492 M
+(   9.    Security Considerations  . . . . . . . . . . . . . . . . . . 12) s
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+(   9.1   Pseudo-Random Number Generation  . . . . . . . . . . . . . . 12) s
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+(   9.2   Transport  . . . . . . . . . . . . . . . . . . . . . . . . . 13) s
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+(   9.2.1 Confidentiality  . . . . . . . . . . . . . . . . . . . . . . 13) s
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+(   9.2.2 Data Integrity . . . . . . . . . . . . . . . . . . . . . . . 16) s
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+(   9.2.3 Replay . . . . . . . . . . . . . . . . . . . . . . . . . . . 16) s
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+(   9.2.4 Man-in-the-middle  . . . . . . . . . . . . . . . . . . . . . 17) s
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+(   9.2.5 Denial-of-service  . . . . . . . . . . . . . . . . . . . . . 19) s
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+(   9.2.6 Covert Channels  . . . . . . . . . . . . . . . . . . . . . . 19) s
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+(   9.2.7 Forward Secrecy  . . . . . . . . . . . . . . . . . . . . . . 20) s
+5 382 M
+(   9.3   Authentication Protocol  . . . . . . . . . . . . . . . . . . 20) s
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+(   9.3.1 Weak Transport . . . . . . . . . . . . . . . . . . . . . . . 21) s
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+(   9.3.2 Debug messages . . . . . . . . . . . . . . . . . . . . . . . 21) s
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+(   9.3.3 Local security policy  . . . . . . . . . . . . . . . . . . . 21) s
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+(   9.3.4 Public key authentication  . . . . . . . . . . . . . . . . . 22) s
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+(   9.3.5 Password authentication  . . . . . . . . . . . . . . . . . . 22) s
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+(   9.3.6 Host based authentication  . . . . . . . . . . . . . . . . . 23) s
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+(   9.4   Connection protocol  . . . . . . . . . . . . . . . . . . . . 23) s
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+(   9.4.1 End point security . . . . . . . . . . . . . . . . . . . . . 23) s
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+(   9.4.2 Proxy forwarding . . . . . . . . . . . . . . . . . . . . . . 23) s
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+(   9.4.3 X11 forwarding . . . . . . . . . . . . . . . . . . . . . . . 24) s
+5 261 M
+(         Normative References . . . . . . . . . . . . . . . . . . . . 24) s
+5 250 M
+(         Informative References . . . . . . . . . . . . . . . . . . . 25) s
+5 239 M
+(         Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 27) s
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+(         Intellectual Property and Copyright Statements . . . . . . . 28) s
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+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
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+(1. Contributors) s
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+(   The major original contributors of this document were: Tatu Ylonen,) s
+5 657 M
+(   Tero Kivinen, Timo J. Rinne, Sami Lehtinen \(all of SSH Communications) s
+5 646 M
+(   Security Corp\), and Markku-Juhani O. Saarinen \(University of) s
+5 635 M
+(   Jyvaskyla\)) s
+5 613 M
+(   The document editor is: [email protected].  Comments on this) s
+5 602 M
+(   internet draft should be sent to the IETF SECSH working group,) s
+5 591 M
+(   details at: http://ietf.org/html.charters/secsh-charter.html) s
+5 569 M
+(2. Introduction) s
+5 547 M
+(   SSH is a protocol for secure remote login and other secure network) s
+5 536 M
+(   services over an insecure network.  It consists of three major) s
+5 525 M
+(   components:) s
+5 514 M
+(   o  The Transport Layer Protocol [SSH-TRANS] provides server) s
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+(      authentication, confidentiality, and integrity. It may optionally) s
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+(      also provide compression. The transport layer will typically be) s
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+(      run over a TCP/IP connection, but might also be used on top of any) s
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+(      other reliable data stream.) s
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+(   o  The User Authentication Protocol [SSH-USERAUTH] authenticates the) s
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+(      client-side user to the server. It runs over the transport layer) s
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+(      protocol.) s
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+(   o  The Connection Protocol [SSH-CONNECT] multiplexes the encrypted) s
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+(      tunnel into several logical channels. It runs over the user) s
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+(      authentication protocol.) s
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+(   The client sends a service request once a secure transport layer) s
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+(   connection has been established. A second service request is sent) s
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+(   after user authentication is complete. This allows new protocols to) s
+5 349 M
+(   be defined and coexist with the protocols listed above.) s
+5 327 M
+(   The connection protocol provides channels that can be used for a wide) s
+5 316 M
+(   range of purposes. Standard methods are provided for setting up) s
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+(   secure interactive shell sessions and for forwarding \("tunneling"\)) s
+5 294 M
+(   arbitrary TCP/IP ports and X11 connections.) s
+5 272 M
+(3. Specification of Requirements) s
+5 250 M
+(   All documents related to the SSH protocols shall use the keywords) s
+5 239 M
+(   "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD",) s
+5 228 M
+(   "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" to describe) s
+5 217 M
+(   requirements.  They are to be interpreted as described in [RFC2119].) s
+5 195 M
+(4. Architecture) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                 [Page 3]) s
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+(4.1 Host Keys) s
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+(   Each server host SHOULD have a host key.  Hosts MAY have multiple) s
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+(   host keys using multiple different algorithms.  Multiple hosts MAY) s
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+(   share the same host key. If a host has keys at all, it MUST have at) s
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+(   least one key using each REQUIRED public key algorithm \(DSS) s
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+(   [FIPS-186]\).) s
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+(   The server host key is used during key exchange to verify that the) s
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+(   client is really talking to the correct server. For this to be) s
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+(   possible, the client must have a priori knowledge of the server's) s
+5 569 M
+(   public host key.) s
+5 547 M
+(   Two different trust models can be used:) s
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+(   o  The client has a local database that associates each host name \(as) s
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+(      typed by the user\) with the corresponding public host key.  This) s
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+(      method requires no centrally administered infrastructure, and no) s
+5 503 M
+(      third-party coordination.  The downside is that the database of) s
+5 492 M
+(      name-to-key associations may become burdensome to maintain.) s
+5 481 M
+(   o  The host name-to-key association is certified by some trusted) s
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+(      certification authority.  The client only knows the CA root key,) s
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+(      and can verify the validity of all host keys certified by accepted) s
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+(      CAs.) s
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+(      The second alternative eases the maintenance problem, since) s
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+(      ideally only a single CA key needs to be securely stored on the) s
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+(      client.  On the other hand, each host key must be appropriately) s
+5 393 M
+(      certified by a central authority before authorization is possible.) s
+5 382 M
+(      Also, a lot of trust is placed on the central infrastructure.) s
+5 360 M
+(   The protocol provides the option that the server name - host key) s
+5 349 M
+(   association is not checked when connecting to the host for the first) s
+5 338 M
+(   time. This allows communication without prior communication of host) s
+5 327 M
+(   keys or certification. The connection still provides protection) s
+5 316 M
+(   against passive listening; however, it becomes vulnerable to active) s
+5 305 M
+(   man-in-the-middle attacks. Implementations SHOULD NOT normally allow) s
+5 294 M
+(   such connections by default, as they pose a potential security) s
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+(   problem. However, as there is no widely deployed key infrastructure) s
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+(   available on the Internet yet, this option makes the protocol much) s
+5 261 M
+(   more usable during the transition time until such an infrastructure) s
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+(   emerges, while still providing a much higher level of security than) s
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+(   that offered by older solutions \(e.g. telnet [RFC-854] and rlogin) s
+5 228 M
+(   [RFC-1282]\).) s
+5 206 M
+(   Implementations SHOULD try to make the best effort to check host) s
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+(   keys.  An example of a possible strategy is to only accept a host key) s
+5 184 M
+(   without checking the first time a host is connected, save the key in) s
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+(   connections to that host.) s
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+(   Implementations MAY provide additional methods for verifying the) s
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+(   verified by using telephone or other external communication channels.) s
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+(   All implementations SHOULD provide an option to not accept host keys) s
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+(   that cannot be verified.) s
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+(   We believe that ease of use is critical to end-user acceptance of) s
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+(4.2 Extensibility) s
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+(   We believe that the protocol will evolve over time, and some) s
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+(   organizations will want to use their own encryption, authentication) s
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+(   and/or key exchange methods.  Central registration of all extensions) s
+5 448 M
+(   is cumbersome, especially for experimental or classified features.) s
+5 437 M
+(   On the other hand, having no central registration leads to conflicts) s
+5 426 M
+(   in method identifiers, making interoperability difficult.) s
+5 404 M
+(   We have chosen to identify algorithms, methods, formats, and) s
+5 393 M
+(   extension protocols with textual names that are of a specific format.) s
+5 382 M
+(   DNS names are used to create local namespaces where experimental or) s
+5 371 M
+(   classified extensions can be defined without fear of conflicts with) s
+5 360 M
+(   other implementations.) s
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+(   One design goal has been to keep the base protocol as simple as) s
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+(   possible, and to require as few algorithms as possible.  However, all) s
+5 316 M
+(   implementations MUST support a minimal set of algorithms to ensure) s
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+(   interoperability \(this does not imply that the local policy on all) s
+5 294 M
+(   hosts would necessary allow these algorithms\).  The mandatory) s
+5 283 M
+(   algorithms are specified in the relevant protocol documents.) s
+5 261 M
+(   Additional algorithms, methods, formats, and extension protocols can) s
+5 250 M
+(   be defined in separate drafts.  See Section Algorithm Naming \(Section) s
+5 239 M
+(   6\) for more information.) s
+5 217 M
+(4.3 Policy Issues) s
+5 195 M
+(   The protocol allows full negotiation of encryption, integrity, key) s
+5 184 M
+(   exchange, compression, and public key algorithms and formats.) s
+5 173 M
+(   Encryption, integrity, public key, and compression algorithms can be) s
+5 129 M
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+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 6 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(   different for each direction.) s
+5 668 M
+(   The following policy issues SHOULD be addressed in the configuration) s
+5 657 M
+(   mechanisms of each implementation:) s
+5 646 M
+(   o  Encryption, integrity, and compression algorithms, separately for) s
+5 635 M
+(      each direction.  The policy MUST specify which is the preferred) s
+5 624 M
+(      algorithm \(e.g. the first algorithm listed in each category\).) s
+5 613 M
+(   o  Public key algorithms and key exchange method to be used for host) s
+5 602 M
+(      authentication.  The existence of trusted host keys for different) s
+5 591 M
+(      public key algorithms also affects this choice.) s
+5 580 M
+(   o  The authentication methods that are to be required by the server) s
+5 569 M
+(      for each user.  The server's policy MAY require multiple) s
+5 558 M
+(      authentication for some or all users.  The required algorithms MAY) s
+5 547 M
+(      depend on the location where the user is trying to log in from.) s
+5 536 M
+(   o  The operations that the user is allowed to perform using the) s
+5 525 M
+(      connection protocol.  Some issues are related to security; for) s
+5 514 M
+(      example, the policy SHOULD NOT allow the server to start sessions) s
+5 503 M
+(      or run commands on the client machine, and MUST NOT allow) s
+5 492 M
+(      connections to the authentication agent unless forwarding such) s
+5 481 M
+(      connections has been requested.  Other issues, such as which TCP/) s
+5 470 M
+(      IP ports can be forwarded and by whom, are clearly issues of local) s
+5 459 M
+(      policy. Many of these issues may involve traversing or bypassing) s
+5 448 M
+(      firewalls, and are interrelated with the local security policy.) s
+5 426 M
+(4.4 Security Properties) s
+5 404 M
+(   The primary goal of the SSH protocol is improved security on the) s
+5 393 M
+(   Internet.  It attempts to do this in a way that is easy to deploy,) s
+5 382 M
+(   even at the cost of absolute security.) s
+5 371 M
+(   o  All encryption, integrity, and public key algorithms used are) s
+5 360 M
+(      well-known, well-established algorithms.) s
+5 349 M
+(   o  All algorithms are used with cryptographically sound key sizes) s
+5 338 M
+(      that are believed to provide protection against even the strongest) s
+5 327 M
+(      cryptanalytic attacks for decades.) s
+5 316 M
+(   o  All algorithms are negotiated, and in case some algorithm is) s
+5 305 M
+(      broken, it is easy to switch to some other algorithm without) s
+5 294 M
+(      modifying the base protocol.) s
+5 272 M
+(   Specific concessions were made to make wide-spread fast deployment) s
+5 261 M
+(   easier.  The particular case where this comes up is verifying that) s
+5 250 M
+(   the server host key really belongs to the desired host; the protocol) s
+5 239 M
+(   allows the verification to be left out \(but this is NOT RECOMMENDED\).) s
+5 228 M
+(   This is believed to significantly improve usability in the short) s
+5 217 M
+(   term, until widespread Internet public key infrastructures emerge.) s
+5 195 M
+(4.5 Packet Size and Overhead) s
+5 173 M
+(   Some readers will worry about the increase in packet size due to new) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                 [Page 6]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (6,7) 4
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 7 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(   headers, padding, and MAC.  The minimum packet size is in the order) s
+5 679 M
+(   of 28 bytes \(depending on negotiated algorithms\).  The increase is) s
+5 668 M
+(   negligible for large packets, but very significant for one-byte) s
+5 657 M
+(   packets \(telnet-type sessions\).  There are, however, several factors) s
+5 646 M
+(   that make this a non-issue in almost all cases:) s
+5 635 M
+(   o  The minimum size of a TCP/IP header is 32 bytes.  Thus, the) s
+5 624 M
+(      increase is actually from 33 to 51 bytes \(roughly\).) s
+5 613 M
+(   o  The minimum size of the data field of an Ethernet packet is 46) s
+5 602 M
+(      bytes [RFC-894]. Thus, the increase is no more than 5 bytes. When) s
+5 591 M
+(      Ethernet headers are considered, the increase is less than 10) s
+5 580 M
+(      percent.) s
+5 569 M
+(   o  The total fraction of telnet-type data in the Internet is) s
+5 558 M
+(      negligible, even with increased packet sizes.) s
+5 536 M
+(   The only environment where the packet size increase is likely to have) s
+5 525 M
+(   a significant effect is PPP [RFC-1134] over slow modem lines \(PPP) s
+5 514 M
+(   compresses the TCP/IP headers, emphasizing the increase in packet) s
+5 503 M
+(   size\). However, with modern modems, the time needed to transfer is in) s
+5 492 M
+(   the order of 2 milliseconds, which is a lot faster than people can) s
+5 481 M
+(   type.) s
+5 459 M
+(   There are also issues related to the maximum packet size.  To) s
+5 448 M
+(   minimize delays in screen updates, one does not want excessively) s
+5 437 M
+(   large packets for interactive sessions.  The maximum packet size is) s
+5 426 M
+(   negotiated separately for each channel.) s
+5 404 M
+(4.6 Localization and Character Set Support) s
+5 382 M
+(   For the most part, the SSH protocols do not directly pass text that) s
+5 371 M
+(   would be displayed to the user. However, there are some places where) s
+5 360 M
+(   such data might be passed. When applicable, the character set for the) s
+5 349 M
+(   data MUST be explicitly specified. In most places, ISO 10646 with) s
+5 338 M
+(   UTF-8 encoding is used [RFC-2279]. When applicable, a field is also) s
+5 327 M
+(   provided for a language tag [RFC-3066].) s
+5 305 M
+(   One big issue is the character set of the interactive session.  There) s
+5 294 M
+(   is no clear solution, as different applications may display data in) s
+5 283 M
+(   different formats.  Different types of terminal emulation may also be) s
+5 272 M
+(   employed in the client, and the character set to be used is) s
+5 261 M
+(   effectively determined by the terminal emulation.  Thus, no place is) s
+5 250 M
+(   provided for directly specifying the character set or encoding for) s
+5 239 M
+(   terminal session data.  However, the terminal emulation type \(e.g.) s
+5 228 M
+(   "vt100"\) is transmitted to the remote site, and it implicitly) s
+5 217 M
+(   specifies the character set and encoding.  Applications typically use) s
+5 206 M
+(   the terminal type to determine what character set they use, or the) s
+5 195 M
+(   character set is determined using some external means.  The terminal) s
+5 184 M
+(   emulation may also allow configuring the default character set.  In) s
+5 173 M
+(   any case, the character set for the terminal session is considered) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                 [Page 7]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 8 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(   primarily a client local issue.) s
+5 668 M
+(   Internal names used to identify algorithms or protocols are normally) s
+5 657 M
+(   never displayed to users, and must be in US-ASCII.) s
+5 635 M
+(   The client and server user names are inherently constrained by what) s
+5 624 M
+(   the server is prepared to accept.  They might, however, occasionally) s
+5 613 M
+(   be displayed in logs, reports, etc.  They MUST be encoded using ISO) s
+5 602 M
+(   10646 UTF-8, but other encodings may be required in some cases.  It) s
+5 591 M
+(   is up to the server to decide how to map user names to accepted user) s
+5 580 M
+(   names.  Straight bit-wise binary comparison is RECOMMENDED.) s
+5 558 M
+(   For localization purposes, the protocol attempts to minimize the) s
+5 547 M
+(   number of textual messages transmitted.  When present, such messages) s
+5 536 M
+(   typically relate to errors, debugging information, or some externally) s
+5 525 M
+(   configured data.  For data that is normally displayed, it SHOULD be) s
+5 514 M
+(   possible to fetch a localized message instead of the transmitted) s
+5 503 M
+(   message by using a numerical code. The remaining messages SHOULD be) s
+5 492 M
+(   configurable.) s
+5 470 M
+(5. Data Type Representations Used in the SSH Protocols) s
+5 459 M
+(   byte) s
+5 437 M
+(      A byte represents an arbitrary 8-bit value \(octet\) [RFC-1700].) s
+5 426 M
+(      Fixed length data is sometimes represented as an array of bytes,) s
+5 415 M
+(      written byte[n], where n is the number of bytes in the array.) s
+5 393 M
+(   boolean) s
+5 371 M
+(      A boolean value is stored as a single byte.  The value 0) s
+5 360 M
+(      represents FALSE, and the value 1 represents TRUE. All non-zero) s
+5 349 M
+(      values MUST be interpreted as TRUE; however, applications MUST NOT) s
+5 338 M
+(      store values other than 0 and 1.) s
+5 316 M
+(   uint32) s
+5 294 M
+(      Represents a 32-bit unsigned integer.  Stored as four bytes in the) s
+5 283 M
+(      order of decreasing significance \(network byte order\). For) s
+5 272 M
+(      example, the value 699921578 \(0x29b7f4aa\) is stored as 29 b7 f4) s
+5 261 M
+(      aa.) s
+5 239 M
+(   uint64) s
+5 217 M
+(      Represents a 64-bit unsigned integer.  Stored as eight bytes in) s
+5 206 M
+(      the order of decreasing significance \(network byte order\).) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                 [Page 8]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (8,9) 5
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 9 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(   string) s
+5 668 M
+(      Arbitrary length binary string.  Strings are allowed to contain) s
+5 657 M
+(      arbitrary binary data, including null characters and 8-bit) s
+5 646 M
+(      characters. They are stored as a uint32 containing its length) s
+5 635 M
+(      \(number of bytes that follow\) and zero \(= empty string\) or more) s
+5 624 M
+(      bytes that are the value of the string.  Terminating null) s
+5 613 M
+(      characters are not used.) s
+5 591 M
+(      Strings are also used to store text.  In that case, US-ASCII is) s
+5 580 M
+(      used for internal names, and ISO-10646 UTF-8 for text that might) s
+5 569 M
+(      be displayed to the user. The terminating null character SHOULD) s
+5 558 M
+(      NOT normally be stored in the string.) s
+5 536 M
+(      For example, the US-ASCII string "testing" is represented as 00 00) s
+5 525 M
+(      00 07 t e s t i n g. The UTF8 mapping does not alter the encoding) s
+5 514 M
+(      of US-ASCII characters.) s
+5 492 M
+(   mpint) s
+5 470 M
+(      Represents multiple precision integers in two's complement format,) s
+5 459 M
+(      stored as a string, 8 bits per byte, MSB first. Negative numbers) s
+5 448 M
+(      have the value 1 as the most significant bit of the first byte of) s
+5 437 M
+(      the data partition. If the most significant bit would be set for a) s
+5 426 M
+(      positive number, the number MUST be preceded by a zero byte.) s
+5 415 M
+(      Unnecessary leading bytes with the value 0 or 255 MUST NOT be) s
+5 404 M
+(      included.  The value zero MUST be stored as a string with zero) s
+5 393 M
+(      bytes of data.) s
+5 371 M
+(      By convention, a number that is used in modular computations in) s
+5 360 M
+(      Z_n SHOULD be represented in the range 0 <= x < n.) s
+5 338 M
+(       Examples:) s
+5 327 M
+(       value \(hex\)        representation \(hex\)) s
+5 316 M
+(       ---------------------------------------------------------------) s
+5 305 M
+(       0                  00 00 00 00) s
+5 294 M
+(       9a378f9b2e332a7    00 00 00 08 09 a3 78 f9 b2 e3 32 a7) s
+5 283 M
+(       80                 00 00 00 02 00 80) s
+5 272 M
+(       -1234              00 00 00 02 ed cc) s
+5 261 M
+(       -deadbeef          00 00 00 05 ff 21 52 41 11) s
+5 217 M
+(   name-list) s
+5 195 M
+(      A string containing a comma separated list of names. A name list) s
+5 184 M
+(      is represented as a uint32 containing its length \(number of bytes) s
+5 173 M
+(      that follow\) followed by a comma-separated list of zero or more) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                 [Page 9]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 10 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(      names. A name MUST be non-zero length, and it MUST NOT contain a) s
+5 679 M
+(      comma \(','\). Context may impose additional restrictions on the) s
+5 668 M
+(      names; for example, the names in a list may have to be valid) s
+5 657 M
+(      algorithm identifier \(see Algorithm Naming below\), or [RFC-3066]) s
+5 646 M
+(      language tags. The order of the names in a list may or may not be) s
+5 635 M
+(      significant, also depending on the context where the list is is) s
+5 624 M
+(      used. Terminating NUL characters are not used, neither for the) s
+5 613 M
+(      individual names, nor for the list as a whole.) s
+5 591 M
+(       Examples:) s
+5 580 M
+(       value              representation \(hex\)) s
+5 569 M
+(       ---------------------------------------) s
+5 558 M
+(       \(\), the empty list 00 00 00 00) s
+5 547 M
+(       \("zlib"\)           00 00 00 04 7a 6c 69 62) s
+5 536 M
+(       \("zlib", "none"\)   00 00 00 09 7a 6c 69 62 2c 6e 6f 6e 65) s
+5 481 M
+(6. Algorithm Naming) s
+5 459 M
+(   The SSH protocols refer to particular hash, encryption, integrity,) s
+5 448 M
+(   compression, and key exchange algorithms or protocols by names.) s
+5 437 M
+(   There are some standard algorithms that all implementations MUST) s
+5 426 M
+(   support. There are also algorithms that are defined in the protocol) s
+5 415 M
+(   specification but are OPTIONAL.  Furthermore, it is expected that) s
+5 404 M
+(   some organizations will want to use their own algorithms.) s
+5 382 M
+(   In this protocol, all algorithm identifiers MUST be printable) s
+5 371 M
+(   US-ASCII non-empty strings no longer than 64 characters. Names MUST) s
+5 360 M
+(   be case-sensitive.) s
+5 338 M
+(   There are two formats for algorithm names:) s
+5 327 M
+(   o  Names that do not contain an at-sign \(@\) are reserved to be) s
+5 316 M
+(      assigned by IETF consensus \(RFCs\).  Examples include `3des-cbc',) s
+5 305 M
+(      `sha-1', `hmac-sha1', and `zlib' \(the quotes are not part of the) s
+5 294 M
+(      name\).  Names of this format MUST NOT be used without first) s
+5 283 M
+(      registering them.  Registered names MUST NOT contain an at-sign) s
+5 272 M
+(      \(@\) or a comma \(,\).) s
+5 261 M
+(   o  Anyone can define additional algorithms by using names in the) s
+5 250 M
+(      format name@domainname, e.g. "[email protected]". The) s
+5 239 M
+(      format of the part preceding the at sign is not specified; it MUST) s
+5 228 M
+(      consist of US-ASCII characters except at-sign and comma. The part) s
+5 217 M
+(      following the at-sign MUST be a valid fully qualified internet) s
+5 206 M
+(      domain name [RFC-1034] controlled by the person or organization) s
+5 195 M
+(      defining the name. It is up to each domain how it manages its) s
+5 184 M
+(      local namespace.) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                [Page 10]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (10,11) 6
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 11 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(7. Message Numbers) s
+5 668 M
+(   SSH packets have message numbers in the range 1 to 255. These numbers) s
+5 657 M
+(   have been allocated as follows:) s
+5 624 M
+(     Transport layer protocol:) s
+5 602 M
+(       1 to 19    Transport layer generic \(e.g. disconnect, ignore, debug,) s
+5 591 M
+(                  etc.\)) s
+5 580 M
+(       20 to 29   Algorithm negotiation) s
+5 569 M
+(       30 to 49   Key exchange method specific \(numbers can be reused for) s
+5 558 M
+(                  different authentication methods\)) s
+5 536 M
+(     User authentication protocol:) s
+5 514 M
+(       50 to 59   User authentication generic) s
+5 503 M
+(       60 to 79   User authentication method specific \(numbers can be) s
+5 492 M
+(                  reused for different authentication methods\)) s
+5 470 M
+(     Connection protocol:) s
+5 448 M
+(       80 to 89   Connection protocol generic) s
+5 437 M
+(       90 to 127  Channel related messages) s
+5 415 M
+(     Reserved for client protocols:) s
+5 393 M
+(       128 to 191 Reserved) s
+5 371 M
+(     Local extensions:) s
+5 349 M
+(       192 to 255 Local extensions) s
+5 305 M
+(8. IANA Considerations) s
+5 283 M
+(   The initial state of the IANA registry is detailed in [SSH-NUMBERS].) s
+5 261 M
+(   Allocation of the following types of names in the SSH protocols is) s
+5 250 M
+(   assigned by IETF consensus:) s
+5 239 M
+(   o  SSH encryption algorithm names,) s
+5 228 M
+(   o  SSH MAC algorithm names,) s
+5 217 M
+(   o  SSH public key algorithm names \(public key algorithm also implies) s
+5 206 M
+(      encoding and signature/encryption capability\),) s
+5 195 M
+(   o  SSH key exchange method names, and) s
+5 184 M
+(   o  SSH protocol \(service\) names.) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                [Page 11]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 12 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(   These names MUST be printable US-ASCII strings, and MUST NOT contain) s
+5 679 M
+(   the characters at-sign \('@'\), comma \(','\), or whitespace or control) s
+5 668 M
+(   characters \(ASCII codes 32 or less\).  Names are case-sensitive, and) s
+5 657 M
+(   MUST NOT be longer than 64 characters.) s
+5 635 M
+(   Names with the at-sign \('@'\) in them are allocated by the owner of) s
+5 624 M
+(   DNS name after the at-sign \(hierarchical allocation in [RFC-2343]\),) s
+5 613 M
+(   otherwise the same restrictions as above.) s
+5 591 M
+(   Each category of names listed above has a separate namespace.) s
+5 580 M
+(   However, using the same name in multiple categories SHOULD be avoided) s
+5 569 M
+(   to minimize confusion.) s
+5 547 M
+(   Message numbers \(see Section Message Numbers \(Section 7\)\) in the) s
+5 536 M
+(   range of 0..191 are allocated via IETF consensus; message numbers in) s
+5 525 M
+(   the 192..255 range \(the "Local extensions" set\) are reserved for) s
+5 514 M
+(   private use.) s
+5 492 M
+(9. Security Considerations) s
+5 470 M
+(   In order to make the entire body of Security Considerations more) s
+5 459 M
+(   accessible, Security Considerations for the transport,) s
+5 448 M
+(   authentication, and connection documents have been gathered here.) s
+5 426 M
+(   The transport protocol [1] provides a confidential channel over an) s
+5 415 M
+(   insecure network.  It performs server host authentication, key) s
+5 404 M
+(   exchange, encryption, and integrity protection.  It also derives a) s
+5 393 M
+(   unique session id that may be used by higher-level protocols.) s
+5 371 M
+(   The authentication protocol [2] provides a suite of mechanisms which) s
+5 360 M
+(   can be used to authenticate the client user to the server.) s
+5 349 M
+(   Individual mechanisms specified in the in authentication protocol use) s
+5 338 M
+(   the session id provided by the transport protocol and/or depend on) s
+5 327 M
+(   the security and integrity guarantees of the transport protocol.) s
+5 305 M
+(   The connection protocol [3] specifies a mechanism to multiplex) s
+5 294 M
+(   multiple streams [channels] of data over the confidential and) s
+5 283 M
+(   authenticated transport. It also specifies channels for accessing an) s
+5 272 M
+(   interactive shell, for 'proxy-forwarding' various external protocols) s
+5 261 M
+(   over the secure transport \(including arbitrary TCP/IP protocols\), and) s
+5 250 M
+(   for accessing secure 'subsystems' on the server host.) s
+5 228 M
+(9.1 Pseudo-Random Number Generation) s
+5 206 M
+(   This protocol binds each session key to the session by including) s
+5 195 M
+(   random, session specific data in the hash used to produce session) s
+5 184 M
+(   keys.  Special care should be taken to ensure that all of the random) s
+5 173 M
+(   numbers are of good quality.  If the random data here \(e.g., DH) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                [Page 12]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (12,13) 7
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 13 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(   parameters\) are pseudo-random then the pseudo-random number generator) s
+5 679 M
+(   should be cryptographically secure \(i.e., its next output not easily) s
+5 668 M
+(   guessed even when knowing all previous outputs\) and, furthermore,) s
+5 657 M
+(   proper entropy needs to be added to the pseudo-random number) s
+5 646 M
+(   generator.  RFC 1750 [1750] offers suggestions for sources of random) s
+5 635 M
+(   numbers and entropy.  Implementors should note the importance of) s
+5 624 M
+(   entropy and the well-meant, anecdotal warning about the difficulty in) s
+5 613 M
+(   properly implementing pseudo-random number generating functions.) s
+5 591 M
+(   The amount of entropy available to a given client or server may) s
+5 580 M
+(   sometimes be less than what is required.  In this case one must) s
+5 569 M
+(   either resort to pseudo-random number generation regardless of) s
+5 558 M
+(   insufficient entropy or refuse to run the protocol.  The latter is) s
+5 547 M
+(   preferable.) s
+5 525 M
+(9.2 Transport) s
+5 503 M
+(9.2.1 Confidentiality) s
+5 481 M
+(   It is beyond the scope of this document and the Secure Shell Working) s
+5 470 M
+(   Group to analyze or recommend specific ciphers other than the ones) s
+5 459 M
+(   which have been established and accepted within the industry.  At the) s
+5 448 M
+(   time of this writing, ciphers commonly in use include 3DES, ARCFOUR,) s
+5 437 M
+(   twofish, serpent and blowfish.  AES has been accepted by The) s
+5 426 M
+(   published as a US Federal Information Processing Standards [FIPS-197]) s
+5 415 M
+(   and the cryptographic community as being acceptable for this purpose) s
+5 404 M
+(   as well has accepted AES.  As always, implementors and users should) s
+5 393 M
+(   check current literature to ensure that no recent vulnerabilities) s
+5 382 M
+(   have been found in ciphers used within products.  Implementors should) s
+5 371 M
+(   also check to see which ciphers are considered to be relatively) s
+5 360 M
+(   stronger than others and should recommend their use to users over) s
+5 349 M
+(   relatively weaker ciphers.  It would be considered good form for an) s
+5 338 M
+(   implementation to politely and unobtrusively notify a user that a) s
+5 327 M
+(   stronger cipher is available and should be used when a weaker one is) s
+5 316 M
+(   actively chosen.) s
+5 294 M
+(   The "none" cipher is provided for debugging and SHOULD NOT be used) s
+5 283 M
+(   except for that purpose.  It's cryptographic properties are) s
+5 272 M
+(   sufficiently described in RFC 2410, which will show that its use does) s
+5 261 M
+(   not meet the intent of this protocol.) s
+5 239 M
+(   The relative merits of these and other ciphers may also be found in) s
+5 228 M
+(   current literature.  Two references that may provide information on) s
+5 217 M
+(   the subject are [SCHNEIER] and [KAUFMAN,PERLMAN,SPECINER].  Both of) s
+5 206 M
+(   these describe the CBC mode of operation of certain ciphers and the) s
+5 195 M
+(   weakness of this scheme.  Essentially, this mode is theoretically) s
+5 184 M
+(   vulnerable to chosen cipher-text attacks because of the high) s
+5 173 M
+(   predictability of the start of packet sequence.  However, this attack) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                [Page 13]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 14 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(   is still deemed difficult and not considered fully practicable) s
+5 679 M
+(   especially if relatively longer block sizes are used.) s
+5 657 M
+(   Additionally, another CBC mode attack may be mitigated through the) s
+5 646 M
+(   insertion of packets containing SSH_MSG_IGNORE.  Without this) s
+5 635 M
+(   technique, a specific attack may be successful.  For this attack) s
+5 624 M
+(   \(commonly known as the Rogaway attack) s
+5 613 M
+(   [ROGAWAY],[DAI],[BELLARE,KOHNO,NAMPREMPRE]\) to work, the attacker) s
+5 602 M
+(   would need to know the IV of the next block that is going to be) s
+5 591 M
+(   encrypted.  In CBC mode that is the output of the encryption of the) s
+5 580 M
+(   previous block. If the attacker does not have any way to see the) s
+5 569 M
+(   packet yet \(i.e it is in the internal buffers of the ssh) s
+5 558 M
+(   implementation or even in the kernel\) then this attack will not work.) s
+5 547 M
+(   If the last packet has been sent out to the network \(i.e the attacker) s
+5 536 M
+(   has access to it\) then he can use the attack.) s
+5 514 M
+(   In the optimal case an implementor would need to add an extra packet) s
+5 503 M
+(   only if the packet has been sent out onto the network and there are) s
+5 492 M
+(   no other packets waiting for transmission. Implementors may wish to) s
+5 481 M
+(   check to see if there are any unsent packets awaiting transmission,) s
+5 470 M
+(   but unfortunately it is not normally easy to obtain this information) s
+5 459 M
+(   from the kernel or buffers.  If there are not, then a packet) s
+5 448 M
+(   containing SSH_MSG_IGNORE SHOULD be sent.  If a new packet is added) s
+5 437 M
+(   to the stream every time the attacker knows the IV that is supposed) s
+5 426 M
+(   to be used for the next packet, then the attacker will not be able to) s
+5 415 M
+(   guess the correct IV, thus the attack will never be successfull.) s
+5 393 M
+(   As an example, consider the following case:) s
+5 360 M
+(         Client                                                  Server) s
+5 349 M
+(         ------                                                  ------) s
+5 338 M
+(         TCP\(seq=x, len=500\)            ->) s
+5 327 M
+(         contains Record 1) s
+5 305 M
+(                             [500 ms passes, no ACK]) s
+5 283 M
+(        TCP\(seq=x, len=1000\)            ->) s
+5 272 M
+(         contains Records 1,2) s
+5 250 M
+(                                                                   ACK) s
+5 217 M
+(   1.  The Nagle algorithm + TCP retransmits mean that the two records) s
+5 206 M
+(       get coalesced into a single TCP segment) s
+5 195 M
+(   2.  Record 2 is *not* at the beginning of the TCP segment and never) s
+5 184 M
+(       will be, since it gets ACKed.) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                [Page 14]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (14,15) 8
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 15 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(   3.  Yet, the attack is possible because Record 1 has already been) s
+5 679 M
+(       seen.) s
+5 657 M
+(   As this example indicates, it's totally unsafe to use the existence) s
+5 646 M
+(   of unflushed data in the TCP buffers proper as a guide to whether you) s
+5 635 M
+(   need an empty packet, since when you do the second write\(\), the) s
+5 624 M
+(   buffers will contain the un-ACKed Record 1.) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                [Page 15]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 16 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(   On the other hand, it's perfectly safe to have the following) s
+5 679 M
+(   situation:) s
+5 646 M
+(         Client                                                  Server) s
+5 635 M
+(         ------                                                  ------) s
+5 624 M
+(         TCP\(seq=x, len=500\)           ->) s
+5 613 M
+(            contains SSH_MSG_IGNORE) s
+5 591 M
+(         TCP\(seq=y, len=500\)           ->) s
+5 580 M
+(            contains Data) s
+5 558 M
+(      Provided that the IV for second SSH Record is fixed after the data for) s
+5 547 M
+(      the Data packet is determined -i.e. you do:) s
+5 536 M
+(           read from user) s
+5 525 M
+(           encrypt null packet) s
+5 514 M
+(           encrypt data packet) s
+5 481 M
+(9.2.2 Data Integrity) s
+5 459 M
+(   This protocol does allow the Data Integrity mechanism to be disabled.) s
+5 448 M
+(   Implementors SHOULD be wary of exposing this feature for any purpose) s
+5 437 M
+(   other than debugging.  Users and administrators SHOULD be explicitly) s
+5 426 M
+(   warned anytime the "none" MAC is enabled.) s
+5 404 M
+(   So long as the "none" MAC is not used, this protocol provides data) s
+5 393 M
+(   integrity.) s
+5 371 M
+(   Because MACs use a 32 bit sequence number, they might start to leak) s
+5 360 M
+(   information after 2**32 packets have been sent.  However, following) s
+5 349 M
+(   the rekeying recommendations should prevent this attack.  The) s
+5 338 M
+(   transport protocol [1] recommends rekeying after one gigabyte of) s
+5 327 M
+(   data, and the smallest possible packet is 16 bytes. Therefore,) s
+5 316 M
+(   rekeying SHOULD happen after 2**28 packets at the very most.) s
+5 294 M
+(9.2.3 Replay) s
+5 272 M
+(   The use of a MAC other than 'none' provides integrity and) s
+5 261 M
+(   authentication.  In addition, the transport protocol provides a) s
+5 250 M
+(   unique session identifier \(bound in part to pseudo-random data that) s
+5 239 M
+(   is part of the algorithm and key exchange process\) that can be used) s
+5 228 M
+(   by higher level protocols to bind data to a given session and prevent) s
+5 217 M
+(   replay of data from prior sessions. For example, the authentication) s
+5 206 M
+(   protocol uses this to prevent replay of signatures from previous) s
+5 195 M
+(   sessions.  Because public key authentication exchanges are) s
+5 184 M
+(   cryptographically bound to the session \(i.e., to the initial key) s
+5 173 M
+(   exchange\) they cannot be successfully replayed in other sessions.) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                [Page 16]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (16,17) 9
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 17 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(   Note that the session ID can be made public without harming the) s
+5 679 M
+(   security of the protocol.) s
+5 657 M
+(   If two session happen to have the same session ID [hash of key) s
+5 646 M
+(   exchanges] then packets from one can be replayed against the other.) s
+5 635 M
+(   It must be stressed that the chances of such an occurrence are,) s
+5 624 M
+(   needless to say, minimal when using modern cryptographic methods.) s
+5 613 M
+(   This is all the more so true when specifying larger hash function) s
+5 602 M
+(   outputs and DH parameters.) s
+5 580 M
+(   Replay detection using monotonically increasing sequence numbers as) s
+5 569 M
+(   input to the MAC, or HMAC in some cases, is described in [RFC2085] />) s
+5 558 M
+(   [RFC2246], [RFC2743], [RFC1964], [RFC2025], and [RFC1510].  The) s
+5 547 M
+(   underlying construct is discussed in [RFC2104].  Essentially a) s
+5 536 M
+(   different sequence number in each packet ensures that at least this) s
+5 525 M
+(   one input to the MAC function will be unique and will provide a) s
+5 514 M
+(   nonrecurring MAC output that is not predictable to an attacker.  If) s
+5 503 M
+(   the session stays active long enough, however, this sequence number) s
+5 492 M
+(   will wrap.  This event may provide an attacker an opportunity to) s
+5 481 M
+(   replay a previously recorded packet with an identical sequence number) s
+5 470 M
+(   but only if the peers have not rekeyed since the transmission of the) s
+5 459 M
+(   first packet with that sequence number.  If the peers have rekeyed,) s
+5 448 M
+(   then the replay will be detected as the MAC check will fail.  For) s
+5 437 M
+(   this reason, it must be emphasized that peers MUST rekey before a) s
+5 426 M
+(   wrap of the sequence numbers.  Naturally, if an attacker does attempt) s
+5 415 M
+(   to replay a captured packet before the peers have rekeyed, then the) s
+5 404 M
+(   receiver of the duplicate packet will not be able to validate the MAC) s
+5 393 M
+(   and it will be discarded.  The reason that the MAC will fail is) s
+5 382 M
+(   because the receiver will formulate a MAC based upon the packet) s
+5 371 M
+(   contents, the shared secret, and the expected sequence number.  Since) s
+5 360 M
+(   the replayed packet will not be using that expected sequence number) s
+5 349 M
+(   \(the sequence number of the replayed packet will have already been) s
+5 338 M
+(   passed by the receiver\) then the calculated MAC will not match the) s
+5 327 M
+(   MAC received with the packet.) s
+5 305 M
+(9.2.4 Man-in-the-middle) s
+5 283 M
+(   This protocol makes no assumptions nor provisions for an) s
+5 272 M
+(   infrastructure or means for distributing the public keys of hosts. It) s
+5 261 M
+(   is expected that this protocol will sometimes be used without first) s
+5 250 M
+(   verifying the association between the server host key and the server) s
+5 239 M
+(   host name.  Such usage is vulnerable to man-in-the-middle attacks.) s
+5 228 M
+(   This section describes this and encourages administrators and users) s
+5 217 M
+(   to understand the importance of verifying this association before any) s
+5 206 M
+(   session is initiated.) s
+5 184 M
+(   There are three cases of man-in-the-middle attacks to consider.  The) s
+5 173 M
+(   first is where an attacker places a device between the client and the) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                [Page 17]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 18 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(   server before the session is initiated.  In this case, the attack) s
+5 679 M
+(   device is trying to mimic the legitimate server and will offer its) s
+5 668 M
+(   public key to the client when the client initiates a session.  If it) s
+5 657 M
+(   were to offer the public key of the server, then it would not be able) s
+5 646 M
+(   to decrypt or sign the transmissions between the legitimate server) s
+5 635 M
+(   and the client unless it also had access to the private-key of the) s
+5 624 M
+(   host.  The attack device will also, simultaneously to this, initiate) s
+5 613 M
+(   a session to the legitimate server masquerading itself as the client.) s
+5 602 M
+(   If the public key of the server had been securely distributed to the) s
+5 591 M
+(   client prior to that session initiation, the key offered to the) s
+5 580 M
+(   client by the attack device will not match the key stored on the) s
+5 569 M
+(   client.  In that case, the user SHOULD be given a warning that the) s
+5 558 M
+(   offered host key does not match the host key cached on the client.) s
+5 547 M
+(   As described in Section 3.1 of [ARCH], the user may be free to accept) s
+5 536 M
+(   the new key and continue the session.  It is RECOMMENDED that the) s
+5 525 M
+(   warning provide sufficient information to the user of the client) s
+5 514 M
+(   device so they may make an informed decision.  If the user chooses to) s
+5 503 M
+(   continue the session with the stored public-key of the server \(not) s
+5 492 M
+(   the public-key offered at the start of the session\), then the session) s
+5 481 M
+(   specific data between the attacker and server will be different) s
+5 470 M
+(   between the client-to-attacker session and the attacker-to-server) s
+5 459 M
+(   sessions due to the randomness discussed above.  From this, the) s
+5 448 M
+(   attacker will not be able to make this attack work since the attacker) s
+5 437 M
+(   will not be able to correctly sign packets containing this session) s
+5 426 M
+(   specific data from the server since he does not have the private key) s
+5 415 M
+(   of that server.) s
+5 393 M
+(   The second case that should be considered is similar to the first) s
+5 382 M
+(   case in that it also happens at the time of connection but this case) s
+5 371 M
+(   points out the need for the secure distribution of server public) s
+5 360 M
+(   keys.  If the server public keys are not securely distributed then) s
+5 349 M
+(   the client cannot know if it is talking to the intended server.  An) s
+5 338 M
+(   attacker may use social engineering techniques to pass off server) s
+5 327 M
+(   keys to unsuspecting users and may then place a man-in-the-middle) s
+5 316 M
+(   attack device between the legitimate server and the clients.  If this) s
+5 305 M
+(   is allowed to happen then the clients will form client-to-attacker) s
+5 294 M
+(   sessions and the attacker will form attacker-to-server sessions and) s
+5 283 M
+(   will be able to monitor and manipulate all of the traffic between the) s
+5 272 M
+(   clients and the legitimate servers.  Server administrators are) s
+5 261 M
+(   encouraged to make host key fingerprints available for checking by) s
+5 250 M
+(   some means whose security does not rely on the integrity of the) s
+5 239 M
+(   actual host keys.  Possible mechanisms are discussed in Section 3.1) s
+5 228 M
+(   of [SSH-ARCH] and may also include secured Web pages, physical pieces) s
+5 217 M
+(   of paper, etc. Implementors SHOULD provide recommendations on how) s
+5 206 M
+(   best to do this with their implementation.  Because the protocol is) s
+5 195 M
+(   extensible, future extensions to the protocol may provide better) s
+5 184 M
+(   mechanisms for dealing with the need to know the server's host key) s
+5 173 M
+(   before connecting.  For example, making the host key fingerprint) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                [Page 18]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (18,19) 10
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 19 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(   available through a secure DNS lookup, or using kerberos over gssapi) s
+5 679 M
+(   during key exchange to authenticate the server are possibilities.) s
+5 657 M
+(   In the third man-in-the-middle case, attackers may attempt to) s
+5 646 M
+(   manipulate packets in transit between peers after the session has) s
+5 635 M
+(   been established.  As described in the Replay part of this section, a) s
+5 624 M
+(   successful attack of this nature is very improbable.  As in the) s
+5 613 M
+(   Replay section, this reasoning does assume that the MAC is secure and) s
+5 602 M
+(   that it is infeasible to construct inputs to a MAC algorithm to give) s
+5 591 M
+(   a known output.  This is discussed in much greater detail in Section) s
+5 580 M
+(   6 of RFC 2104.  If the MAC algorithm has a vulnerability or is weak) s
+5 569 M
+(   enough, then the attacker may be able to specify certain inputs to) s
+5 558 M
+(   yield a known MAC.  With that they may be able to alter the contents) s
+5 547 M
+(   of a packet in transit.  Alternatively the attacker may be able to) s
+5 536 M
+(   exploit the algorithm vulnerability or weakness to find the shared) s
+5 525 M
+(   secret by reviewing the MACs from captured packets.  In either of) s
+5 514 M
+(   those cases, an attacker could construct a packet or packets that) s
+5 503 M
+(   could be inserted into an SSH stream.  To prevent that, implementors) s
+5 492 M
+(   are encouraged to utilize commonly accepted MAC algorithms and) s
+5 481 M
+(   administrators are encouraged to watch current literature and) s
+5 470 M
+(   discussions of cryptography to ensure that they are not using a MAC) s
+5 459 M
+(   algorithm that has a recently found vulnerability or weakness.) s
+5 437 M
+(   In summary, the use of this protocol without a reliable association) s
+5 426 M
+(   of the binding between a host and its host keys is inherently) s
+5 415 M
+(   insecure and is NOT RECOMMENDED.  It may however be necessary in) s
+5 404 M
+(   non-security critical environments, and will still provide protection) s
+5 393 M
+(   against passive attacks.  Implementors of protocols and applications) s
+5 382 M
+(   running on top of this protocol should keep this possibility in mind.) s
+5 360 M
+(9.2.5 Denial-of-service) s
+5 338 M
+(   This protocol is designed to be used over a reliable transport.  If) s
+5 327 M
+(   transmission errors or message manipulation occur, the connection is) s
+5 316 M
+(   closed.  The connection SHOULD be re-established if this occurs.) s
+5 305 M
+(   Denial of service attacks of this type \("wire cutter"\) are almost) s
+5 294 M
+(   impossible to avoid.) s
+5 272 M
+(   In addition, this protocol is vulnerable to Denial of Service attacks) s
+5 261 M
+(   because an attacker can force the server to go through the CPU and) s
+5 250 M
+(   memory intensive tasks of connection setup and key exchange without) s
+5 239 M
+(   authenticating.  Implementors SHOULD provide features that make this) s
+5 228 M
+(   more difficult.  For example, only allowing connections from a subset) s
+5 217 M
+(   of IPs known to have valid users.) s
+5 195 M
+(9.2.6 Covert Channels) s
+5 173 M
+(   The protocol was not designed to eliminate covert channels.  For) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                [Page 19]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 20 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(   example, the padding, SSH_MSG_IGNORE messages, and several other) s
+5 679 M
+(   places in the protocol can be used to pass covert information, and) s
+5 668 M
+(   the recipient has no reliable way to verify whether such information) s
+5 657 M
+(   is being sent.) s
+5 635 M
+(9.2.7 Forward Secrecy) s
+5 613 M
+(   It should be noted that the Diffie-Hellman key exchanges may provide) s
+5 602 M
+(   perfect forward secrecy \(PFS\).  PFS is essentially defined as the) s
+5 591 M
+(   cryptographic property of a key-establishment protocol in which the) s
+5 580 M
+(   compromise of a session key or long-term private key after a given) s
+5 569 M
+(   session does not cause the compromise of any earlier session. [ANSI) s
+5 558 M
+(   T1.523-2001]  SSHv2 sessions resulting from a key exchange using) s
+5 547 M
+(   diffie-hellman-group1-sha1 are secure even if private keying/) s
+5 536 M
+(   authentication material is later revealed, but not if the session) s
+5 525 M
+(   keys are revealed. So, given this definition of PFS, SSHv2 does have) s
+5 514 M
+(   PFS.  It is hoped that all other key exchange mechanisms proposed and) s
+5 503 M
+(   used in the future will also provide PFS.  This property is not) s
+5 492 M
+(   commuted to any of the applications or protocols using SSH as a) s
+5 481 M
+(   transport however.  The transport layer of SSH provides) s
+5 470 M
+(   confidentiality for password authentication and other methods that) s
+5 459 M
+(   rely on secret data.) s
+5 437 M
+(   Of course, if the DH private parameters for the client and server are) s
+5 426 M
+(   revealed then the session key is revealed, but these items can be) s
+5 415 M
+(   thrown away after the key exchange completes.  It's worth pointing) s
+5 404 M
+(   out that these items should not be allowed to end up on swap space) s
+5 393 M
+(   and that they should be erased from memory as soon as the key) s
+5 382 M
+(   exchange completes.) s
+5 360 M
+(9.3 Authentication Protocol) s
+5 338 M
+(   The purpose of this protocol is to perform client user) s
+5 327 M
+(   authentication. It assumes that this run over a secure transport) s
+5 316 M
+(   layer protocol, which has already authenticated the server machine,) s
+5 305 M
+(   established an encrypted communications channel, and computed a) s
+5 294 M
+(   unique session identifier for this session.) s
+5 272 M
+(   Several authentication methods with different security) s
+5 261 M
+(   characteristics are allowed.  It is up to the server's local policy) s
+5 250 M
+(   to decide which methods \(or combinations of methods\) it is willing to) s
+5 239 M
+(   accept for each user.  Authentication is no stronger than the weakest) s
+5 228 M
+(   combination allowed.) s
+5 206 M
+(   The server may go into a "sleep" period after repeated unsuccessful) s
+5 195 M
+(   authentication attempts to make key search more difficult for) s
+5 184 M
+(   attackers.  Care should be taken so that this doesn't become a) s
+5 173 M
+(   self-denial of service vector.) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                [Page 20]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (20,21) 11
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 21 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(9.3.1 Weak Transport) s
+5 668 M
+(   If the transport layer does not provide confidentiality,) s
+5 657 M
+(   authentication methods that rely on secret data SHOULD be disabled.) s
+5 646 M
+(   If it does not provide strong integrity protection, requests to) s
+5 635 M
+(   change authentication data \(e.g. a password change\) SHOULD be) s
+5 624 M
+(   disabled to prevent an attacker from  modifying the ciphertext) s
+5 613 M
+(   without being noticed, or rendering the new authentication data) s
+5 602 M
+(   unusable \(denial of service\).) s
+5 580 M
+(   The assumption as stated above that the Authentication Protocol only) s
+5 569 M
+(   run over a secure transport that has previously authenticated the) s
+5 558 M
+(   server is very important to note.  People deploying SSH are reminded) s
+5 547 M
+(   of the consequences of man-in-the-middle attacks if the client does) s
+5 536 M
+(   not have a very strong a priori association of the server with the) s
+5 525 M
+(   host key of that server.  Specifically for the case of the) s
+5 514 M
+(   Authentication Protocol the client may form a session to a) s
+5 503 M
+(   man-in-the-middle attack device and divulge user credentials such as) s
+5 492 M
+(   their username and password.  Even in the cases of authentication) s
+5 481 M
+(   where no user credentials are divulged, an attacker may still gain) s
+5 470 M
+(   information they shouldn't have by capturing key-strokes in much the) s
+5 459 M
+(   same way that a honeypot works.) s
+5 437 M
+(9.3.2 Debug messages) s
+5 415 M
+(   Special care should be taken when designing debug messages.  These) s
+5 404 M
+(   messages may reveal surprising amounts of information about the host) s
+5 393 M
+(   if not properly designed.  Debug messages can be disabled \(during) s
+5 382 M
+(   user authentication phase\) if high security is required.) s
+5 371 M
+(   Administrators of host machines should make all attempts to) s
+5 360 M
+(   compartmentalize all event notification messages and protect them) s
+5 349 M
+(   from unwarranted observation.  Developers should be aware of the) s
+5 338 M
+(   sensitive nature of some of the normal event messages and debug) s
+5 327 M
+(   messages and may want to provide guidance to administrators on ways) s
+5 316 M
+(   to keep this information away from unauthorized people.  Developers) s
+5 305 M
+(   should consider minimizing the amount of sensitive information) s
+5 294 M
+(   obtainable by users during the authentication phase in accordance) s
+5 283 M
+(   with the local policies.  For this reason, it is RECOMMENDED that) s
+5 272 M
+(   debug messages be initially disabled at the time of deployment and) s
+5 261 M
+(   require an active decision by an administrator to allow them to be) s
+5 250 M
+(   enabled.  It is also RECOMMENDED that a message expressing this) s
+5 239 M
+(   concern be presented to the administrator of a system when the action) s
+5 228 M
+(   is taken to enable debugging messages.) s
+5 206 M
+(9.3.3 Local security policy) s
+5 184 M
+(   Implementer MUST ensure that the credentials provided validate the) s
+5 173 M
+(   professed user and also MUST ensure that the local policy of the) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                [Page 21]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 22 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(   server permits the user the access requested.  In particular, because) s
+5 679 M
+(   of the flexible nature of the SSH connection protocol, it may not be) s
+5 668 M
+(   possible to determine the local security policy, if any, that should) s
+5 657 M
+(   apply at the time of authentication because the kind of service being) s
+5 646 M
+(   requested is not clear at that instant. For example, local policy) s
+5 635 M
+(   might allow a user to access files on the server, but not start an) s
+5 624 M
+(   interactive shell. However, during the authentication protocol, it is) s
+5 613 M
+(   not known whether the user will be accessing files or attempting to) s
+5 602 M
+(   use an interactive shell, or even both.  In any event, where local) s
+5 591 M
+(   security policy for the server host exists, it MUST be applied and) s
+5 580 M
+(   enforced correctly.) s
+5 558 M
+(   Implementors are encouraged to provide a default local policy and) s
+5 547 M
+(   make its parameters known to administrators and users.  At the) s
+5 536 M
+(   discretion of the implementors, this default policy may be along the) s
+5 525 M
+(   lines of 'anything goes' where there are no restrictions placed upon) s
+5 514 M
+(   users, or it may be along the lines of 'excessively restrictive' in) s
+5 503 M
+(   which case the administrators will have to actively make changes to) s
+5 492 M
+(   this policy to meet their needs.  Alternatively, it may be some) s
+5 481 M
+(   attempt at providing something practical and immediately useful to) s
+5 470 M
+(   the administrators of the system so they don't have to put in much) s
+5 459 M
+(   effort to get SSH working.  Whatever choice is made MUST be applied) s
+5 448 M
+(   and enforced as required above.) s
+5 426 M
+(9.3.4 Public key authentication) s
+5 404 M
+(   The use of public-key authentication assumes that the client host has) s
+5 393 M
+(   not been compromised.  It also assumes that the private-key of the) s
+5 382 M
+(   server host has not been compromised.) s
+5 360 M
+(   This risk can be mitigated by the use of passphrases on private keys;) s
+5 349 M
+(   however, this is not an enforceable policy.  The use of smartcards,) s
+5 338 M
+(   or other technology to make passphrases an enforceable policy is) s
+5 327 M
+(   suggested.) s
+5 305 M
+(   The server could require both password and public-key authentication,) s
+5 294 M
+(   however, this requires the client to expose its password to the) s
+5 283 M
+(   server \(see section on password authentication below.\)) s
+5 261 M
+(9.3.5 Password authentication) s
+5 239 M
+(   The password mechanism as specified in the authentication protocol) s
+5 228 M
+(   assumes that the server has not been compromised.  If the server has) s
+5 217 M
+(   been compromised, using password authentication will reveal a valid) s
+5 206 M
+(   username / password combination to the attacker, which may lead to) s
+5 195 M
+(   further compromises.) s
+5 173 M
+(   This vulnerability can be mitigated by using an alternative form of) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                [Page 22]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (22,23) 12
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 23 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(   authentication.  For example, public-key authentication makes no) s
+5 679 M
+(   assumptions about security on the server.) s
+5 657 M
+(9.3.6 Host based authentication) s
+5 635 M
+(   Host based authentication assumes that the client has not been) s
+5 624 M
+(   compromised.  There are no mitigating strategies, other than to use) s
+5 613 M
+(   host based authentication in combination with another authentication) s
+5 602 M
+(   method.) s
+5 580 M
+(9.4 Connection protocol) s
+5 558 M
+(9.4.1 End point security) s
+5 536 M
+(   End point security is assumed by the connection protocol.  If the) s
+5 525 M
+(   server has been compromised, any terminal sessions, port forwarding,) s
+5 514 M
+(   or systems accessed on the host are compromised.  There are no) s
+5 503 M
+(   mitigating factors for this.) s
+5 481 M
+(   If the client end point has been compromised, and the server fails to) s
+5 470 M
+(   stop the attacker at the authentication protocol, all services) s
+5 459 M
+(   exposed \(either as subsystems or through forwarding\) will be) s
+5 448 M
+(   vulnerable to attack.  Implementors SHOULD provide mechanisms for) s
+5 437 M
+(   administrators to control which services are exposed to limit the) s
+5 426 M
+(   vulnerability of other services.) s
+5 404 M
+(   These controls might include controlling which machines and ports can) s
+5 393 M
+(   be target in 'port-forwarding' operations, which users are allowed to) s
+5 382 M
+(   use interactive shell facilities, or which users are allowed to use) s
+5 371 M
+(   exposed subsystems.) s
+5 349 M
+(9.4.2 Proxy forwarding) s
+5 327 M
+(   The SSH connection protocol allows for proxy forwarding of other) s
+5 316 M
+(   protocols such as SNMP, POP3, and HTTP.  This may be a concern for) s
+5 305 M
+(   network administrators who wish to control the access of certain) s
+5 294 M
+(   applications by users located outside of their physical location.) s
+5 283 M
+(   Essentially, the forwarding of these protocols may violate site) s
+5 272 M
+(   specific security policies as they may be undetectably tunneled) s
+5 261 M
+(   through a firewall.  Implementors SHOULD provide an administrative) s
+5 250 M
+(   mechanism to control the proxy forwarding functionality so that site) s
+5 239 M
+(   specific security policies may be upheld.) s
+5 217 M
+(   In addition, a reverse proxy forwarding functionality is available,) s
+5 206 M
+(   which again can be used to bypass firewall controls.) s
+5 184 M
+(   As indicated above, end-point security is assumed during proxy) s
+5 173 M
+(   forwarding operations.  Failure of end-point security will compromise) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                [Page 23]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 24 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(   all data passed over proxy forwarding.) s
+5 668 M
+(9.4.3 X11 forwarding) s
+5 646 M
+(   Another form of proxy forwarding provided by the ssh connection) s
+5 635 M
+(   protocol is the forwarding of the X11 protocol.  If end-point) s
+5 624 M
+(   security has been compromised, X11 forwarding may allow attacks) s
+5 613 M
+(   against the X11 server.  Users and administrators should, as a matter) s
+5 602 M
+(   of course, use appropriate X11 security mechanisms to prevent) s
+5 591 M
+(   unauthorized use of the X11 server.  Implementors, administrators and) s
+5 580 M
+(   users who wish to further explore the security mechanisms of X11 are) s
+5 569 M
+(   invited to read [SCHEIFLER] and analyze previously reported problems) s
+5 558 M
+(   with the interactions between SSH forwarding and X11 in CERT) s
+5 547 M
+(   vulnerabilities VU#363181 and VU#118892 [CERT].) s
+5 525 M
+(   X11 display forwarding with SSH, by itself, is not sufficient to) s
+5 514 M
+(   correct well known problems with X11 security [VENEMA].  However, X11) s
+5 503 M
+(   display forwarding in SSHv2 \(or other, secure protocols\), combined) s
+5 492 M
+(   with actual and pseudo-displays which accept connections only over) s
+5 481 M
+(   local IPC mechanisms authorized by permissions or ACLs, does correct) s
+5 470 M
+(   many X11 security problems as long as the "none" MAC is not used.  It) s
+5 459 M
+(   is RECOMMENDED that X11 display implementations default to allowing) s
+5 448 M
+(   display opens only over local IPC.  It is RECOMMENDED that SSHv2) s
+5 437 M
+(   server implementations that support X11 forwarding default to) s
+5 426 M
+(   allowing display opens only over local IPC.  On single-user systems) s
+5 415 M
+(   it might be reasonable to default to allowing local display opens) s
+5 404 M
+(   over TCP/IP.) s
+5 382 M
+(   Implementors of the X11 forwarding protocol SHOULD implement the) s
+5 371 M
+(   magic cookie access checking spoofing mechanism as described in) s
+5 360 M
+(   [ssh-connect] as an additional mechanism to prevent unauthorized use) s
+5 349 M
+(   of the proxy.) s
+5 327 M
+(Normative References) s
+5 305 M
+(   [SSH-ARCH]) s
+5 294 M
+(              Ylonen, T., "SSH Protocol Architecture", I-D) s
+5 283 M
+(              draft-ietf-architecture-15.txt, Oct 2003.) s
+5 261 M
+(   [SSH-TRANS]) s
+5 250 M
+(              Ylonen, T., "SSH Transport Layer Protocol", I-D) s
+5 239 M
+(              draft-ietf-transport-17.txt, Oct 2003.) s
+5 217 M
+(   [SSH-USERAUTH]) s
+5 206 M
+(              Ylonen, T., "SSH Authentication Protocol", I-D) s
+5 195 M
+(              draft-ietf-userauth-18.txt, Oct 2003.) s
+5 173 M
+(   [SSH-CONNECT]) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                [Page 24]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (24,25) 13
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 25 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(              Ylonen, T., "SSH Connection Protocol", I-D) s
+5 679 M
+(              draft-ietf-connect-18.txt, Oct 2003.) s
+5 657 M
+(   [SSH-NUMBERS]) s
+5 646 M
+(              Lehtinen, S. and D. Moffat, "SSH Protocol Assigned) s
+5 635 M
+(              Numbers", I-D draft-ietf-secsh-assignednumbers-05.txt, Oct) s
+5 624 M
+(              2003.) s
+5 602 M
+(   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate) s
+5 591 M
+(              Requirement Levels", BCP 14, RFC 2119, March 1997.) s
+5 569 M
+(Informative References) s
+5 547 M
+(   [FIPS-186]) s
+5 536 M
+(              Federal Information Processing Standards Publication,) s
+5 525 M
+(              "FIPS PUB 186, Digital Signature Standard", May 1994.) s
+5 503 M
+(   [FIPS-197]) s
+5 492 M
+(              National Institue of Standards and Technology, "FIPS 197,) s
+5 481 M
+(              Specification for the Advanced Encryption Standard",) s
+5 470 M
+(              November 2001.) s
+5 448 M
+(   [ANSI T1.523-2001]) s
+5 437 M
+(              American National Standards Insitute, Inc., "Telecom) s
+5 426 M
+(              Glossary 2000", February 2001.) s
+5 404 M
+(   [SCHEIFLER]) s
+5 393 M
+(              Scheifler, R., "X Window System : The Complete Reference) s
+5 382 M
+(              to Xlib, X Protocol, Icccm, Xlfd, 3rd edition.", Digital) s
+5 371 M
+(              Press ISBN 1555580882, Feburary 1992.) s
+5 349 M
+(   [RFC0854]  Postel, J. and J. Reynolds, "Telnet Protocol) s
+5 338 M
+(              Specification", STD 8, RFC 854, May 1983.) s
+5 316 M
+(   [RFC0894]  Hornig, C., "Standard for the transmission of IP datagrams) s
+5 305 M
+(              over Ethernet networks", STD 41, RFC 894, April 1984.) s
+5 283 M
+(   [RFC1034]  Mockapetris, P., "Domain names - concepts and facilities",) s
+5 272 M
+(              STD 13, RFC 1034, November 1987.) s
+5 250 M
+(   [RFC1134]  Perkins, D., "Point-to-Point Protocol: A proposal for) s
+5 239 M
+(              multi-protocol transmission of datagrams over) s
+5 228 M
+(              Point-to-Point links", RFC 1134, November 1989.) s
+5 206 M
+(   [RFC1282]  Kantor, B., "BSD Rlogin", RFC 1282, December 1991.) s
+5 184 M
+(   [RFC1510]  Kohl, J. and B. Neuman, "The Kerberos Network) s
+5 173 M
+(              Authentication Service \(V5\)", RFC 1510, September 1993.) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                [Page 25]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 26 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
+(   [RFC1700]  Reynolds, J. and J. Postel, "Assigned Numbers", RFC 1700,) s
+5 679 M
+(              October 1994.) s
+5 657 M
+(   [RFC1750]  Eastlake, D., Crocker, S. and J. Schiller, "Randomness) s
+5 646 M
+(              Recommendations for Security", RFC 1750, December 1994.) s
+5 624 M
+(   [RFC3066]  Alvestrand, H., "Tags for the Identification of) s
+5 613 M
+(              Languages", BCP 47, RFC 3066, January 2001.) s
+5 591 M
+(   [RFC1964]  Linn, J., "The Kerberos Version 5 GSS-API Mechanism", RFC) s
+5 580 M
+(              1964, June 1996.) s
+5 558 M
+(   [RFC2025]  Adams, C., "The Simple Public-Key GSS-API Mechanism) s
+5 547 M
+(              \(SPKM\)", RFC 2025, October 1996.) s
+5 525 M
+(   [RFC2085]  Oehler, M. and R. Glenn, "HMAC-MD5 IP Authentication with) s
+5 514 M
+(              Replay Prevention", RFC 2085, February 1997.) s
+5 492 M
+(   [RFC2104]  Krawczyk, H., Bellare, M. and R. Canetti, "HMAC:) s
+5 481 M
+(              Keyed-Hashing for Message Authentication", RFC 2104,) s
+5 470 M
+(              February 1997.) s
+5 448 M
+(   [RFC2246]  Dierks, T., Allen, C., Treese, W., Karlton, P., Freier, A.) s
+5 437 M
+(              and P. Kocher, "The TLS Protocol Version 1.0", RFC 2246,) s
+5 426 M
+(              January 1999.) s
+5 404 M
+(   [RFC2279]  Yergeau, F., "UTF-8, a transformation format of ISO) s
+5 393 M
+(              10646", RFC 2279, January 1998.) s
+5 371 M
+(   [RFC2410]  Glenn, R. and S. Kent, "The NULL Encryption Algorithm and) s
+5 360 M
+(              Its Use With IPsec", RFC 2410, November 1998.) s
+5 338 M
+(   [RFC2434]  Narten, T. and H. Alvestrand, "Guidelines for Writing an) s
+5 327 M
+(              IANA Considerations Section in RFCs", BCP 26, RFC 2434,) s
+5 316 M
+(              October 1998.) s
+5 294 M
+(   [RFC2743]  Linn, J., "Generic Security Service Application Program) s
+5 283 M
+(              Interface Version 2, Update 1", RFC 2743, January 2000.) s
+5 261 M
+(   [SCHNEIER]) s
+5 250 M
+(              Schneier, B., "Applied Cryptography Second Edition:) s
+5 239 M
+(              protocols algorithms and source in code in C", 1996.) s
+5 217 M
+(   [KAUFMAN,PERLMAN,SPECINER]) s
+5 206 M
+(              Kaufman, C., Perlman, R. and M. Speciner, "Network) s
+5 195 M
+(              Security: PRIVATE Communication in a PUBLIC World", 1995.) s
+5 173 M
+(   [CERT]     CERT Coordination Center, The., "http://www.cert.org/nav/) s
+5 129 M
+(Ylonen & Moffat          Expires March 31, 2004                [Page 26]) s
+_R
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+/fname () def
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+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
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+(              index_red.html".) s
+5 668 M
+(   [VENEMA]   Venema, W., "Murphy's Law and Computer Security",) s
+5 657 M
+(              Proceedings of 6th USENIX Security Symposium, San Jose CA) s
+5 646 M
+(              http://www.usenix.org/publications/library/proceedings/) s
+5 635 M
+(              sec96/venema.html, July 1996.) s
+5 613 M
+(   [ROGAWAY]  Rogaway, P., "Problems with Proposed IP Cryptography",) s
+5 602 M
+(              Unpublished paper http://www.cs.ucdavis.edu/~rogaway/) s
+5 591 M
+(              papers/draft-rogaway-ipsec-comments-00.txt, 1996.) s
+5 569 M
+(   [DAI]      Dai, W., "An attack against SSH2 protocol", Email to the) s
+5 558 M
+(              SECSH Working Group [email protected] ftp://) s
+5 547 M
+(              ftp.ietf.org/ietf-mail-archive/secsh/2002-02.mail, Feb) s
+5 536 M
+(              2002.) s
+5 514 M
+(   [BELLARE,KOHNO,NAMPREMPRE]) s
+5 503 M
+(              Bellaire, M., Kohno, T. and C. Namprempre, "Authenticated) s
+5 492 M
+(              Encryption in SSH: Fixing the SSH Binary Packet Protocol",) s
+5 481 M
+(              , Sept 2002.) s
+5 448 M
+(Authors' Addresses) s
+5 426 M
+(   Tatu Ylonen) s
+5 415 M
+(   SSH Communications Security Corp) s
+5 404 M
+(   Fredrikinkatu 42) s
+5 393 M
+(   HELSINKI  FIN-00100) s
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+(   EMail: [email protected]) s
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+(Internet-Draft         SSH Protocol Architecture                Oct 2003) s
+5 690 M
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+5 668 M
+(   The IETF takes no position regarding the validity or scope of any) s
+5 657 M
+(   intellectual property or other rights that might be claimed to) s
+5 646 M
+(   pertain to the implementation or use of the technology described in) s
+5 635 M
+(   this document or the extent to which any license under such rights) s
+5 624 M
+(   might or might not be available; neither does it represent that it) s
+5 613 M
+(   has made any effort to identify any such rights. Information on the) s
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+(   IETF's procedures with respect to rights in standards-track and) s
+5 591 M
+(   standards-related documentation can be found in BCP-11. Copies of) s
+5 580 M
+(   claims of rights made available for publication and any assurances of) s
+5 569 M
+(   licenses to be made available, or the result of an attempt made to) s
+5 558 M
+(   obtain a general license or permission for the use of such) s
+5 547 M
+(   proprietary rights by implementors or users of this specification can) s
+5 536 M
+(   be obtained from the IETF Secretariat.) s
+5 514 M
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+(   copyrights, patents or patent applications, or other proprietary) s
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+(   Director.) s
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+(   document. For more information consult the online list of claimed) s
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+(   revoked by the Internet Society or its successors or assignees.) s
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+(   This document and the information contained herein is provided on an) s
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+(   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING) s
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+(   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING) s
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+(   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION) s
+5 646 M
+(   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF) s
+5 635 M
+(   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.) s
+5 602 M
+(Acknowledgment) s
+5 580 M
+(   Funding for the RFC Editor function is currently provided by the) s
+5 569 M
+(   Internet Society.) s
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+userdict/PStoPSmatrix matrix currentmatrix put
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+%%Trailer
+%%Pages: 29
+%%DocumentNeededResources: font Courier-Bold Courier 
+%%EOF
diff --git a/lib/ssh/doc/standard/draft-ietf-secsh-architecture-15.txt b/lib/ssh/doc/standard/draft-ietf-secsh-architecture-15.txt
new file mode 100644
index 0000000000..18070e8485
--- /dev/null
+++ b/lib/ssh/doc/standard/draft-ietf-secsh-architecture-15.txt
@@ -0,0 +1,1624 @@
+
+
+
+Network Working Group                                          T. Ylonen
+Internet-Draft                          SSH Communications Security Corp
+Expires: March 31, 2004                                   D. Moffat, Ed.
+                                                   Sun Microsystems, Inc
+                                                                Oct 2003
+
+
+                       SSH Protocol Architecture
+                  draft-ietf-secsh-architecture-15.txt
+
+Status of this Memo
+
+   This document is an Internet-Draft and is in full conformance with
+   all provisions of Section 10 of RFC2026.
+
+   Internet-Drafts are working documents of the Internet Engineering
+   Task Force (IETF), its areas, and its working groups. Note that other
+   groups may also distribute working documents as Internet-Drafts.
+
+   Internet-Drafts are draft documents valid for a maximum of six months
+   and may be updated, replaced, or obsoleted by other documents at any
+   time. It is inappropriate to use Internet-Drafts as reference
+   material or to cite them other than as "work in progress."
+
+   The list of current Internet-Drafts can be accessed at http://
+   www.ietf.org/ietf/1id-abstracts.txt.
+
+   The list of Internet-Draft Shadow Directories can be accessed at
+   http://www.ietf.org/shadow.html.
+
+   This Internet-Draft will expire on March 31, 2004.
+
+Copyright Notice
+
+   Copyright (C) The Internet Society (2003). All Rights Reserved.
+
+Abstract
+
+   SSH is a protocol for secure remote login and other secure network
+   services over an insecure network. This document describes the
+   architecture of the SSH protocol, as well as the notation and
+   terminology used in SSH protocol documents. It also discusses the SSH
+   algorithm naming system that allows local extensions. The SSH
+   protocol consists of three major components: The Transport Layer
+   Protocol provides server authentication, confidentiality, and
+   integrity with perfect forward secrecy. The User Authentication
+   Protocol authenticates the client to the server. The Connection
+   Protocol multiplexes the encrypted tunnel into several logical
+   channels. Details of these protocols are described in separate
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                 [Page 1]
+
+Internet-Draft         SSH Protocol Architecture                Oct 2003
+
+
+   documents.
+
+Table of Contents
+
+   1.    Contributors . . . . . . . . . . . . . . . . . . . . . . . .  3
+   2.    Introduction . . . . . . . . . . . . . . . . . . . . . . . .  3
+   3.    Specification of Requirements  . . . . . . . . . . . . . . .  3
+   4.    Architecture . . . . . . . . . . . . . . . . . . . . . . . .  3
+   4.1   Host Keys  . . . . . . . . . . . . . . . . . . . . . . . . .  4
+   4.2   Extensibility  . . . . . . . . . . . . . . . . . . . . . . .  5
+   4.3   Policy Issues  . . . . . . . . . . . . . . . . . . . . . . .  5
+   4.4   Security Properties  . . . . . . . . . . . . . . . . . . . .  6
+   4.5   Packet Size and Overhead . . . . . . . . . . . . . . . . . .  6
+   4.6   Localization and Character Set Support . . . . . . . . . . .  7
+   5.    Data Type Representations Used in the SSH Protocols  . . . .  8
+   6.    Algorithm Naming . . . . . . . . . . . . . . . . . . . . . . 10
+   7.    Message Numbers  . . . . . . . . . . . . . . . . . . . . . . 11
+   8.    IANA Considerations  . . . . . . . . . . . . . . . . . . . . 11
+   9.    Security Considerations  . . . . . . . . . . . . . . . . . . 12
+   9.1   Pseudo-Random Number Generation  . . . . . . . . . . . . . . 12
+   9.2   Transport  . . . . . . . . . . . . . . . . . . . . . . . . . 13
+   9.2.1 Confidentiality  . . . . . . . . . . . . . . . . . . . . . . 13
+   9.2.2 Data Integrity . . . . . . . . . . . . . . . . . . . . . . . 16
+   9.2.3 Replay . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
+   9.2.4 Man-in-the-middle  . . . . . . . . . . . . . . . . . . . . . 17
+   9.2.5 Denial-of-service  . . . . . . . . . . . . . . . . . . . . . 19
+   9.2.6 Covert Channels  . . . . . . . . . . . . . . . . . . . . . . 19
+   9.2.7 Forward Secrecy  . . . . . . . . . . . . . . . . . . . . . . 20
+   9.3   Authentication Protocol  . . . . . . . . . . . . . . . . . . 20
+   9.3.1 Weak Transport . . . . . . . . . . . . . . . . . . . . . . . 21
+   9.3.2 Debug messages . . . . . . . . . . . . . . . . . . . . . . . 21
+   9.3.3 Local security policy  . . . . . . . . . . . . . . . . . . . 21
+   9.3.4 Public key authentication  . . . . . . . . . . . . . . . . . 22
+   9.3.5 Password authentication  . . . . . . . . . . . . . . . . . . 22
+   9.3.6 Host based authentication  . . . . . . . . . . . . . . . . . 23
+   9.4   Connection protocol  . . . . . . . . . . . . . . . . . . . . 23
+   9.4.1 End point security . . . . . . . . . . . . . . . . . . . . . 23
+   9.4.2 Proxy forwarding . . . . . . . . . . . . . . . . . . . . . . 23
+   9.4.3 X11 forwarding . . . . . . . . . . . . . . . . . . . . . . . 24
+         Normative References . . . . . . . . . . . . . . . . . . . . 24
+         Informative References . . . . . . . . . . . . . . . . . . . 25
+         Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 27
+         Intellectual Property and Copyright Statements . . . . . . . 28
+
+
+
+
+
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                 [Page 2]
+
+Internet-Draft         SSH Protocol Architecture                Oct 2003
+
+
+1. Contributors
+
+   The major original contributors of this document were: Tatu Ylonen,
+   Tero Kivinen, Timo J. Rinne, Sami Lehtinen (all of SSH Communications
+   Security Corp), and Markku-Juhani O. Saarinen (University of
+   Jyvaskyla)
+
+   The document editor is: [email protected].  Comments on this
+   internet draft should be sent to the IETF SECSH working group,
+   details at: http://ietf.org/html.charters/secsh-charter.html
+
+2. Introduction
+
+   SSH is a protocol for secure remote login and other secure network
+   services over an insecure network.  It consists of three major
+   components:
+   o  The Transport Layer Protocol [SSH-TRANS] provides server
+      authentication, confidentiality, and integrity. It may optionally
+      also provide compression. The transport layer will typically be
+      run over a TCP/IP connection, but might also be used on top of any
+      other reliable data stream.
+   o  The User Authentication Protocol [SSH-USERAUTH] authenticates the
+      client-side user to the server. It runs over the transport layer
+      protocol.
+   o  The Connection Protocol [SSH-CONNECT] multiplexes the encrypted
+      tunnel into several logical channels. It runs over the user
+      authentication protocol.
+
+   The client sends a service request once a secure transport layer
+   connection has been established. A second service request is sent
+   after user authentication is complete. This allows new protocols to
+   be defined and coexist with the protocols listed above.
+
+   The connection protocol provides channels that can be used for a wide
+   range of purposes. Standard methods are provided for setting up
+   secure interactive shell sessions and for forwarding ("tunneling")
+   arbitrary TCP/IP ports and X11 connections.
+
+3. Specification of Requirements
+
+   All documents related to the SSH protocols shall use the keywords
+   "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD",
+   "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" to describe
+   requirements.  They are to be interpreted as described in [RFC2119].
+
+4. Architecture
+
+
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                 [Page 3]
+
+Internet-Draft         SSH Protocol Architecture                Oct 2003
+
+
+4.1 Host Keys
+
+   Each server host SHOULD have a host key.  Hosts MAY have multiple
+   host keys using multiple different algorithms.  Multiple hosts MAY
+   share the same host key. If a host has keys at all, it MUST have at
+   least one key using each REQUIRED public key algorithm (DSS
+   [FIPS-186]).
+
+   The server host key is used during key exchange to verify that the
+   client is really talking to the correct server. For this to be
+   possible, the client must have a priori knowledge of the server's
+   public host key.
+
+   Two different trust models can be used:
+   o  The client has a local database that associates each host name (as
+      typed by the user) with the corresponding public host key.  This
+      method requires no centrally administered infrastructure, and no
+      third-party coordination.  The downside is that the database of
+      name-to-key associations may become burdensome to maintain.
+   o  The host name-to-key association is certified by some trusted
+      certification authority.  The client only knows the CA root key,
+      and can verify the validity of all host keys certified by accepted
+      CAs.
+
+      The second alternative eases the maintenance problem, since
+      ideally only a single CA key needs to be securely stored on the
+      client.  On the other hand, each host key must be appropriately
+      certified by a central authority before authorization is possible.
+      Also, a lot of trust is placed on the central infrastructure.
+
+   The protocol provides the option that the server name - host key
+   association is not checked when connecting to the host for the first
+   time. This allows communication without prior communication of host
+   keys or certification. The connection still provides protection
+   against passive listening; however, it becomes vulnerable to active
+   man-in-the-middle attacks. Implementations SHOULD NOT normally allow
+   such connections by default, as they pose a potential security
+   problem. However, as there is no widely deployed key infrastructure
+   available on the Internet yet, this option makes the protocol much
+   more usable during the transition time until such an infrastructure
+   emerges, while still providing a much higher level of security than
+   that offered by older solutions (e.g. telnet [RFC-854] and rlogin
+   [RFC-1282]).
+
+   Implementations SHOULD try to make the best effort to check host
+   keys.  An example of a possible strategy is to only accept a host key
+   without checking the first time a host is connected, save the key in
+   a local database, and compare against that key on all future
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                 [Page 4]
+
+Internet-Draft         SSH Protocol Architecture                Oct 2003
+
+
+   connections to that host.
+
+   Implementations MAY provide additional methods for verifying the
+   correctness of host keys, e.g. a hexadecimal fingerprint derived from
+   the SHA-1 hash of the public key. Such fingerprints can easily be
+   verified by using telephone or other external communication channels.
+
+   All implementations SHOULD provide an option to not accept host keys
+   that cannot be verified.
+
+   We believe that ease of use is critical to end-user acceptance of
+   security solutions, and no improvement in security is gained if the
+   new solutions are not used.  Thus, providing the option not to check
+   the server host key is believed to improve the overall security of
+   the Internet, even though it reduces the security of the protocol in
+   configurations where it is allowed.
+
+4.2 Extensibility
+
+   We believe that the protocol will evolve over time, and some
+   organizations will want to use their own encryption, authentication
+   and/or key exchange methods.  Central registration of all extensions
+   is cumbersome, especially for experimental or classified features.
+   On the other hand, having no central registration leads to conflicts
+   in method identifiers, making interoperability difficult.
+
+   We have chosen to identify algorithms, methods, formats, and
+   extension protocols with textual names that are of a specific format.
+   DNS names are used to create local namespaces where experimental or
+   classified extensions can be defined without fear of conflicts with
+   other implementations.
+
+   One design goal has been to keep the base protocol as simple as
+   possible, and to require as few algorithms as possible.  However, all
+   implementations MUST support a minimal set of algorithms to ensure
+   interoperability (this does not imply that the local policy on all
+   hosts would necessary allow these algorithms).  The mandatory
+   algorithms are specified in the relevant protocol documents.
+
+   Additional algorithms, methods, formats, and extension protocols can
+   be defined in separate drafts.  See Section Algorithm Naming (Section
+   6) for more information.
+
+4.3 Policy Issues
+
+   The protocol allows full negotiation of encryption, integrity, key
+   exchange, compression, and public key algorithms and formats.
+   Encryption, integrity, public key, and compression algorithms can be
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                 [Page 5]
+
+Internet-Draft         SSH Protocol Architecture                Oct 2003
+
+
+   different for each direction.
+
+   The following policy issues SHOULD be addressed in the configuration
+   mechanisms of each implementation:
+   o  Encryption, integrity, and compression algorithms, separately for
+      each direction.  The policy MUST specify which is the preferred
+      algorithm (e.g. the first algorithm listed in each category).
+   o  Public key algorithms and key exchange method to be used for host
+      authentication.  The existence of trusted host keys for different
+      public key algorithms also affects this choice.
+   o  The authentication methods that are to be required by the server
+      for each user.  The server's policy MAY require multiple
+      authentication for some or all users.  The required algorithms MAY
+      depend on the location where the user is trying to log in from.
+   o  The operations that the user is allowed to perform using the
+      connection protocol.  Some issues are related to security; for
+      example, the policy SHOULD NOT allow the server to start sessions
+      or run commands on the client machine, and MUST NOT allow
+      connections to the authentication agent unless forwarding such
+      connections has been requested.  Other issues, such as which TCP/
+      IP ports can be forwarded and by whom, are clearly issues of local
+      policy. Many of these issues may involve traversing or bypassing
+      firewalls, and are interrelated with the local security policy.
+
+4.4 Security Properties
+
+   The primary goal of the SSH protocol is improved security on the
+   Internet.  It attempts to do this in a way that is easy to deploy,
+   even at the cost of absolute security.
+   o  All encryption, integrity, and public key algorithms used are
+      well-known, well-established algorithms.
+   o  All algorithms are used with cryptographically sound key sizes
+      that are believed to provide protection against even the strongest
+      cryptanalytic attacks for decades.
+   o  All algorithms are negotiated, and in case some algorithm is
+      broken, it is easy to switch to some other algorithm without
+      modifying the base protocol.
+
+   Specific concessions were made to make wide-spread fast deployment
+   easier.  The particular case where this comes up is verifying that
+   the server host key really belongs to the desired host; the protocol
+   allows the verification to be left out (but this is NOT RECOMMENDED).
+   This is believed to significantly improve usability in the short
+   term, until widespread Internet public key infrastructures emerge.
+
+4.5 Packet Size and Overhead
+
+   Some readers will worry about the increase in packet size due to new
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                 [Page 6]
+
+Internet-Draft         SSH Protocol Architecture                Oct 2003
+
+
+   headers, padding, and MAC.  The minimum packet size is in the order
+   of 28 bytes (depending on negotiated algorithms).  The increase is
+   negligible for large packets, but very significant for one-byte
+   packets (telnet-type sessions).  There are, however, several factors
+   that make this a non-issue in almost all cases:
+   o  The minimum size of a TCP/IP header is 32 bytes.  Thus, the
+      increase is actually from 33 to 51 bytes (roughly).
+   o  The minimum size of the data field of an Ethernet packet is 46
+      bytes [RFC-894]. Thus, the increase is no more than 5 bytes. When
+      Ethernet headers are considered, the increase is less than 10
+      percent.
+   o  The total fraction of telnet-type data in the Internet is
+      negligible, even with increased packet sizes.
+
+   The only environment where the packet size increase is likely to have
+   a significant effect is PPP [RFC-1134] over slow modem lines (PPP
+   compresses the TCP/IP headers, emphasizing the increase in packet
+   size). However, with modern modems, the time needed to transfer is in
+   the order of 2 milliseconds, which is a lot faster than people can
+   type.
+
+   There are also issues related to the maximum packet size.  To
+   minimize delays in screen updates, one does not want excessively
+   large packets for interactive sessions.  The maximum packet size is
+   negotiated separately for each channel.
+
+4.6 Localization and Character Set Support
+
+   For the most part, the SSH protocols do not directly pass text that
+   would be displayed to the user. However, there are some places where
+   such data might be passed. When applicable, the character set for the
+   data MUST be explicitly specified. In most places, ISO 10646 with
+   UTF-8 encoding is used [RFC-2279]. When applicable, a field is also
+   provided for a language tag [RFC-3066].
+
+   One big issue is the character set of the interactive session.  There
+   is no clear solution, as different applications may display data in
+   different formats.  Different types of terminal emulation may also be
+   employed in the client, and the character set to be used is
+   effectively determined by the terminal emulation.  Thus, no place is
+   provided for directly specifying the character set or encoding for
+   terminal session data.  However, the terminal emulation type (e.g.
+   "vt100") is transmitted to the remote site, and it implicitly
+   specifies the character set and encoding.  Applications typically use
+   the terminal type to determine what character set they use, or the
+   character set is determined using some external means.  The terminal
+   emulation may also allow configuring the default character set.  In
+   any case, the character set for the terminal session is considered
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                 [Page 7]
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+
+
+   primarily a client local issue.
+
+   Internal names used to identify algorithms or protocols are normally
+   never displayed to users, and must be in US-ASCII.
+
+   The client and server user names are inherently constrained by what
+   the server is prepared to accept.  They might, however, occasionally
+   be displayed in logs, reports, etc.  They MUST be encoded using ISO
+   10646 UTF-8, but other encodings may be required in some cases.  It
+   is up to the server to decide how to map user names to accepted user
+   names.  Straight bit-wise binary comparison is RECOMMENDED.
+
+   For localization purposes, the protocol attempts to minimize the
+   number of textual messages transmitted.  When present, such messages
+   typically relate to errors, debugging information, or some externally
+   configured data.  For data that is normally displayed, it SHOULD be
+   possible to fetch a localized message instead of the transmitted
+   message by using a numerical code. The remaining messages SHOULD be
+   configurable.
+
+5. Data Type Representations Used in the SSH Protocols
+   byte
+
+      A byte represents an arbitrary 8-bit value (octet) [RFC-1700].
+      Fixed length data is sometimes represented as an array of bytes,
+      written byte[n], where n is the number of bytes in the array.
+
+   boolean
+
+      A boolean value is stored as a single byte.  The value 0
+      represents FALSE, and the value 1 represents TRUE. All non-zero
+      values MUST be interpreted as TRUE; however, applications MUST NOT
+      store values other than 0 and 1.
+
+   uint32
+
+      Represents a 32-bit unsigned integer.  Stored as four bytes in the
+      order of decreasing significance (network byte order). For
+      example, the value 699921578 (0x29b7f4aa) is stored as 29 b7 f4
+      aa.
+
+   uint64
+
+      Represents a 64-bit unsigned integer.  Stored as eight bytes in
+      the order of decreasing significance (network byte order).
+
+
+
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                 [Page 8]
+
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+
+
+   string
+
+      Arbitrary length binary string.  Strings are allowed to contain
+      arbitrary binary data, including null characters and 8-bit
+      characters. They are stored as a uint32 containing its length
+      (number of bytes that follow) and zero (= empty string) or more
+      bytes that are the value of the string.  Terminating null
+      characters are not used.
+
+      Strings are also used to store text.  In that case, US-ASCII is
+      used for internal names, and ISO-10646 UTF-8 for text that might
+      be displayed to the user. The terminating null character SHOULD
+      NOT normally be stored in the string.
+
+      For example, the US-ASCII string "testing" is represented as 00 00
+      00 07 t e s t i n g. The UTF8 mapping does not alter the encoding
+      of US-ASCII characters.
+
+   mpint
+
+      Represents multiple precision integers in two's complement format,
+      stored as a string, 8 bits per byte, MSB first. Negative numbers
+      have the value 1 as the most significant bit of the first byte of
+      the data partition. If the most significant bit would be set for a
+      positive number, the number MUST be preceded by a zero byte.
+      Unnecessary leading bytes with the value 0 or 255 MUST NOT be
+      included.  The value zero MUST be stored as a string with zero
+      bytes of data.
+
+      By convention, a number that is used in modular computations in
+      Z_n SHOULD be represented in the range 0 <= x < n.
+
+       Examples:
+       value (hex)        representation (hex)
+       ---------------------------------------------------------------
+       0                  00 00 00 00
+       9a378f9b2e332a7    00 00 00 08 09 a3 78 f9 b2 e3 32 a7
+       80                 00 00 00 02 00 80
+       -1234              00 00 00 02 ed cc
+       -deadbeef          00 00 00 05 ff 21 52 41 11
+
+
+
+   name-list
+
+      A string containing a comma separated list of names. A name list
+      is represented as a uint32 containing its length (number of bytes
+      that follow) followed by a comma-separated list of zero or more
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                 [Page 9]
+
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+
+
+      names. A name MUST be non-zero length, and it MUST NOT contain a
+      comma (','). Context may impose additional restrictions on the
+      names; for example, the names in a list may have to be valid
+      algorithm identifier (see Algorithm Naming below), or [RFC-3066]
+      language tags. The order of the names in a list may or may not be
+      significant, also depending on the context where the list is is
+      used. Terminating NUL characters are not used, neither for the
+      individual names, nor for the list as a whole.
+
+       Examples:
+       value              representation (hex)
+       ---------------------------------------
+       (), the empty list 00 00 00 00
+       ("zlib")           00 00 00 04 7a 6c 69 62
+       ("zlib", "none")   00 00 00 09 7a 6c 69 62 2c 6e 6f 6e 65
+
+
+
+
+6. Algorithm Naming
+
+   The SSH protocols refer to particular hash, encryption, integrity,
+   compression, and key exchange algorithms or protocols by names.
+   There are some standard algorithms that all implementations MUST
+   support. There are also algorithms that are defined in the protocol
+   specification but are OPTIONAL.  Furthermore, it is expected that
+   some organizations will want to use their own algorithms.
+
+   In this protocol, all algorithm identifiers MUST be printable
+   US-ASCII non-empty strings no longer than 64 characters. Names MUST
+   be case-sensitive.
+
+   There are two formats for algorithm names:
+   o  Names that do not contain an at-sign (@) are reserved to be
+      assigned by IETF consensus (RFCs).  Examples include `3des-cbc',
+      `sha-1', `hmac-sha1', and `zlib' (the quotes are not part of the
+      name).  Names of this format MUST NOT be used without first
+      registering them.  Registered names MUST NOT contain an at-sign
+      (@) or a comma (,).
+   o  Anyone can define additional algorithms by using names in the
+      format name@domainname, e.g. "[email protected]". The
+      format of the part preceding the at sign is not specified; it MUST
+      consist of US-ASCII characters except at-sign and comma. The part
+      following the at-sign MUST be a valid fully qualified internet
+      domain name [RFC-1034] controlled by the person or organization
+      defining the name. It is up to each domain how it manages its
+      local namespace.
+
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 10]
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+
+
+7. Message Numbers
+
+   SSH packets have message numbers in the range 1 to 255. These numbers
+   have been allocated as follows:
+
+
+     Transport layer protocol:
+
+       1 to 19    Transport layer generic (e.g. disconnect, ignore, debug,
+                  etc.)
+       20 to 29   Algorithm negotiation
+       30 to 49   Key exchange method specific (numbers can be reused for
+                  different authentication methods)
+
+     User authentication protocol:
+
+       50 to 59   User authentication generic
+       60 to 79   User authentication method specific (numbers can be
+                  reused for different authentication methods)
+
+     Connection protocol:
+
+       80 to 89   Connection protocol generic
+       90 to 127  Channel related messages
+
+     Reserved for client protocols:
+
+       128 to 191 Reserved
+
+     Local extensions:
+
+       192 to 255 Local extensions
+
+
+
+8. IANA Considerations
+
+   The initial state of the IANA registry is detailed in [SSH-NUMBERS].
+
+   Allocation of the following types of names in the SSH protocols is
+   assigned by IETF consensus:
+   o  SSH encryption algorithm names,
+   o  SSH MAC algorithm names,
+   o  SSH public key algorithm names (public key algorithm also implies
+      encoding and signature/encryption capability),
+   o  SSH key exchange method names, and
+   o  SSH protocol (service) names.
+
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 11]
+
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+
+
+   These names MUST be printable US-ASCII strings, and MUST NOT contain
+   the characters at-sign ('@'), comma (','), or whitespace or control
+   characters (ASCII codes 32 or less).  Names are case-sensitive, and
+   MUST NOT be longer than 64 characters.
+
+   Names with the at-sign ('@') in them are allocated by the owner of
+   DNS name after the at-sign (hierarchical allocation in [RFC-2343]),
+   otherwise the same restrictions as above.
+
+   Each category of names listed above has a separate namespace.
+   However, using the same name in multiple categories SHOULD be avoided
+   to minimize confusion.
+
+   Message numbers (see Section Message Numbers (Section 7)) in the
+   range of 0..191 are allocated via IETF consensus; message numbers in
+   the 192..255 range (the "Local extensions" set) are reserved for
+   private use.
+
+9. Security Considerations
+
+   In order to make the entire body of Security Considerations more
+   accessible, Security Considerations for the transport,
+   authentication, and connection documents have been gathered here.
+
+   The transport protocol [1] provides a confidential channel over an
+   insecure network.  It performs server host authentication, key
+   exchange, encryption, and integrity protection.  It also derives a
+   unique session id that may be used by higher-level protocols.
+
+   The authentication protocol [2] provides a suite of mechanisms which
+   can be used to authenticate the client user to the server.
+   Individual mechanisms specified in the in authentication protocol use
+   the session id provided by the transport protocol and/or depend on
+   the security and integrity guarantees of the transport protocol.
+
+   The connection protocol [3] specifies a mechanism to multiplex
+   multiple streams [channels] of data over the confidential and
+   authenticated transport. It also specifies channels for accessing an
+   interactive shell, for 'proxy-forwarding' various external protocols
+   over the secure transport (including arbitrary TCP/IP protocols), and
+   for accessing secure 'subsystems' on the server host.
+
+9.1 Pseudo-Random Number Generation
+
+   This protocol binds each session key to the session by including
+   random, session specific data in the hash used to produce session
+   keys.  Special care should be taken to ensure that all of the random
+   numbers are of good quality.  If the random data here (e.g., DH
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 12]
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+
+
+   parameters) are pseudo-random then the pseudo-random number generator
+   should be cryptographically secure (i.e., its next output not easily
+   guessed even when knowing all previous outputs) and, furthermore,
+   proper entropy needs to be added to the pseudo-random number
+   generator.  RFC 1750 [1750] offers suggestions for sources of random
+   numbers and entropy.  Implementors should note the importance of
+   entropy and the well-meant, anecdotal warning about the difficulty in
+   properly implementing pseudo-random number generating functions.
+
+   The amount of entropy available to a given client or server may
+   sometimes be less than what is required.  In this case one must
+   either resort to pseudo-random number generation regardless of
+   insufficient entropy or refuse to run the protocol.  The latter is
+   preferable.
+
+9.2 Transport
+
+9.2.1 Confidentiality
+
+   It is beyond the scope of this document and the Secure Shell Working
+   Group to analyze or recommend specific ciphers other than the ones
+   which have been established and accepted within the industry.  At the
+   time of this writing, ciphers commonly in use include 3DES, ARCFOUR,
+   twofish, serpent and blowfish.  AES has been accepted by The
+   published as a US Federal Information Processing Standards [FIPS-197]
+   and the cryptographic community as being acceptable for this purpose
+   as well has accepted AES.  As always, implementors and users should
+   check current literature to ensure that no recent vulnerabilities
+   have been found in ciphers used within products.  Implementors should
+   also check to see which ciphers are considered to be relatively
+   stronger than others and should recommend their use to users over
+   relatively weaker ciphers.  It would be considered good form for an
+   implementation to politely and unobtrusively notify a user that a
+   stronger cipher is available and should be used when a weaker one is
+   actively chosen.
+
+   The "none" cipher is provided for debugging and SHOULD NOT be used
+   except for that purpose.  It's cryptographic properties are
+   sufficiently described in RFC 2410, which will show that its use does
+   not meet the intent of this protocol.
+
+   The relative merits of these and other ciphers may also be found in
+   current literature.  Two references that may provide information on
+   the subject are [SCHNEIER] and [KAUFMAN,PERLMAN,SPECINER].  Both of
+   these describe the CBC mode of operation of certain ciphers and the
+   weakness of this scheme.  Essentially, this mode is theoretically
+   vulnerable to chosen cipher-text attacks because of the high
+   predictability of the start of packet sequence.  However, this attack
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 13]
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+
+
+   is still deemed difficult and not considered fully practicable
+   especially if relatively longer block sizes are used.
+
+   Additionally, another CBC mode attack may be mitigated through the
+   insertion of packets containing SSH_MSG_IGNORE.  Without this
+   technique, a specific attack may be successful.  For this attack
+   (commonly known as the Rogaway attack
+   [ROGAWAY],[DAI],[BELLARE,KOHNO,NAMPREMPRE]) to work, the attacker
+   would need to know the IV of the next block that is going to be
+   encrypted.  In CBC mode that is the output of the encryption of the
+   previous block. If the attacker does not have any way to see the
+   packet yet (i.e it is in the internal buffers of the ssh
+   implementation or even in the kernel) then this attack will not work.
+   If the last packet has been sent out to the network (i.e the attacker
+   has access to it) then he can use the attack.
+
+   In the optimal case an implementor would need to add an extra packet
+   only if the packet has been sent out onto the network and there are
+   no other packets waiting for transmission. Implementors may wish to
+   check to see if there are any unsent packets awaiting transmission,
+   but unfortunately it is not normally easy to obtain this information
+   from the kernel or buffers.  If there are not, then a packet
+   containing SSH_MSG_IGNORE SHOULD be sent.  If a new packet is added
+   to the stream every time the attacker knows the IV that is supposed
+   to be used for the next packet, then the attacker will not be able to
+   guess the correct IV, thus the attack will never be successfull.
+
+   As an example, consider the following case:
+
+
+         Client                                                  Server
+         ------                                                  ------
+         TCP(seq=x, len=500)		->
+   	 contains Record 1
+
+                             [500 ms passes, no ACK]
+
+   	TCP(seq=x, len=1000)		->
+   	 contains Records 1,2
+
+                                                                   ACK
+
+
+   1.  The Nagle algorithm + TCP retransmits mean that the two records
+       get coalesced into a single TCP segment
+   2.  Record 2 is *not* at the beginning of the TCP segment and never
+       will be, since it gets ACKed.
+
+
+
+
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+
+
+   3.  Yet, the attack is possible because Record 1 has already been
+       seen.
+
+   As this example indicates, it's totally unsafe to use the existence
+   of unflushed data in the TCP buffers proper as a guide to whether you
+   need an empty packet, since when you do the second write(), the
+   buffers will contain the un-ACKed Record 1.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 15]
+
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+
+
+   On the other hand, it's perfectly safe to have the following
+   situation:
+
+
+         Client                                                  Server
+         ------                                                  ------
+         TCP(seq=x, len=500)           ->
+            contains SSH_MSG_IGNORE
+
+         TCP(seq=y, len=500)           ->
+            contains Data
+
+      Provided that the IV for second SSH Record is fixed after the data for
+      the Data packet is determined -i.e. you do:
+           read from user
+           encrypt null packet
+           encrypt data packet
+
+
+9.2.2 Data Integrity
+
+   This protocol does allow the Data Integrity mechanism to be disabled.
+   Implementors SHOULD be wary of exposing this feature for any purpose
+   other than debugging.  Users and administrators SHOULD be explicitly
+   warned anytime the "none" MAC is enabled.
+
+   So long as the "none" MAC is not used, this protocol provides data
+   integrity.
+
+   Because MACs use a 32 bit sequence number, they might start to leak
+   information after 2**32 packets have been sent.  However, following
+   the rekeying recommendations should prevent this attack.  The
+   transport protocol [1] recommends rekeying after one gigabyte of
+   data, and the smallest possible packet is 16 bytes. Therefore,
+   rekeying SHOULD happen after 2**28 packets at the very most.
+
+9.2.3 Replay
+
+   The use of a MAC other than 'none' provides integrity and
+   authentication.  In addition, the transport protocol provides a
+   unique session identifier (bound in part to pseudo-random data that
+   is part of the algorithm and key exchange process) that can be used
+   by higher level protocols to bind data to a given session and prevent
+   replay of data from prior sessions. For example, the authentication
+   protocol uses this to prevent replay of signatures from previous
+   sessions.  Because public key authentication exchanges are
+   cryptographically bound to the session (i.e., to the initial key
+   exchange) they cannot be successfully replayed in other sessions.
+
+
+
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+
+
+   Note that the session ID can be made public without harming the
+   security of the protocol.
+
+   If two session happen to have the same session ID [hash of key
+   exchanges] then packets from one can be replayed against the other.
+   It must be stressed that the chances of such an occurrence are,
+   needless to say, minimal when using modern cryptographic methods.
+   This is all the more so true when specifying larger hash function
+   outputs and DH parameters.
+
+   Replay detection using monotonically increasing sequence numbers as
+   input to the MAC, or HMAC in some cases, is described in [RFC2085] />
+   [RFC2246], [RFC2743], [RFC1964], [RFC2025], and [RFC1510].  The
+   underlying construct is discussed in [RFC2104].  Essentially a
+   different sequence number in each packet ensures that at least this
+   one input to the MAC function will be unique and will provide a
+   nonrecurring MAC output that is not predictable to an attacker.  If
+   the session stays active long enough, however, this sequence number
+   will wrap.  This event may provide an attacker an opportunity to
+   replay a previously recorded packet with an identical sequence number
+   but only if the peers have not rekeyed since the transmission of the
+   first packet with that sequence number.  If the peers have rekeyed,
+   then the replay will be detected as the MAC check will fail.  For
+   this reason, it must be emphasized that peers MUST rekey before a
+   wrap of the sequence numbers.  Naturally, if an attacker does attempt
+   to replay a captured packet before the peers have rekeyed, then the
+   receiver of the duplicate packet will not be able to validate the MAC
+   and it will be discarded.  The reason that the MAC will fail is
+   because the receiver will formulate a MAC based upon the packet
+   contents, the shared secret, and the expected sequence number.  Since
+   the replayed packet will not be using that expected sequence number
+   (the sequence number of the replayed packet will have already been
+   passed by the receiver) then the calculated MAC will not match the
+   MAC received with the packet.
+
+9.2.4 Man-in-the-middle
+
+   This protocol makes no assumptions nor provisions for an
+   infrastructure or means for distributing the public keys of hosts. It
+   is expected that this protocol will sometimes be used without first
+   verifying the association between the server host key and the server
+   host name.  Such usage is vulnerable to man-in-the-middle attacks.
+   This section describes this and encourages administrators and users
+   to understand the importance of verifying this association before any
+   session is initiated.
+
+   There are three cases of man-in-the-middle attacks to consider.  The
+   first is where an attacker places a device between the client and the
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 17]
+
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+
+
+   server before the session is initiated.  In this case, the attack
+   device is trying to mimic the legitimate server and will offer its
+   public key to the client when the client initiates a session.  If it
+   were to offer the public key of the server, then it would not be able
+   to decrypt or sign the transmissions between the legitimate server
+   and the client unless it also had access to the private-key of the
+   host.  The attack device will also, simultaneously to this, initiate
+   a session to the legitimate server masquerading itself as the client.
+   If the public key of the server had been securely distributed to the
+   client prior to that session initiation, the key offered to the
+   client by the attack device will not match the key stored on the
+   client.  In that case, the user SHOULD be given a warning that the
+   offered host key does not match the host key cached on the client.
+   As described in Section 3.1 of [ARCH], the user may be free to accept
+   the new key and continue the session.  It is RECOMMENDED that the
+   warning provide sufficient information to the user of the client
+   device so they may make an informed decision.  If the user chooses to
+   continue the session with the stored public-key of the server (not
+   the public-key offered at the start of the session), then the session
+   specific data between the attacker and server will be different
+   between the client-to-attacker session and the attacker-to-server
+   sessions due to the randomness discussed above.  From this, the
+   attacker will not be able to make this attack work since the attacker
+   will not be able to correctly sign packets containing this session
+   specific data from the server since he does not have the private key
+   of that server.
+
+   The second case that should be considered is similar to the first
+   case in that it also happens at the time of connection but this case
+   points out the need for the secure distribution of server public
+   keys.  If the server public keys are not securely distributed then
+   the client cannot know if it is talking to the intended server.  An
+   attacker may use social engineering techniques to pass off server
+   keys to unsuspecting users and may then place a man-in-the-middle
+   attack device between the legitimate server and the clients.  If this
+   is allowed to happen then the clients will form client-to-attacker
+   sessions and the attacker will form attacker-to-server sessions and
+   will be able to monitor and manipulate all of the traffic between the
+   clients and the legitimate servers.  Server administrators are
+   encouraged to make host key fingerprints available for checking by
+   some means whose security does not rely on the integrity of the
+   actual host keys.  Possible mechanisms are discussed in Section 3.1
+   of [SSH-ARCH] and may also include secured Web pages, physical pieces
+   of paper, etc. Implementors SHOULD provide recommendations on how
+   best to do this with their implementation.  Because the protocol is
+   extensible, future extensions to the protocol may provide better
+   mechanisms for dealing with the need to know the server's host key
+   before connecting.  For example, making the host key fingerprint
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 18]
+
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+
+
+   available through a secure DNS lookup, or using kerberos over gssapi
+   during key exchange to authenticate the server are possibilities.
+
+   In the third man-in-the-middle case, attackers may attempt to
+   manipulate packets in transit between peers after the session has
+   been established.  As described in the Replay part of this section, a
+   successful attack of this nature is very improbable.  As in the
+   Replay section, this reasoning does assume that the MAC is secure and
+   that it is infeasible to construct inputs to a MAC algorithm to give
+   a known output.  This is discussed in much greater detail in Section
+   6 of RFC 2104.  If the MAC algorithm has a vulnerability or is weak
+   enough, then the attacker may be able to specify certain inputs to
+   yield a known MAC.  With that they may be able to alter the contents
+   of a packet in transit.  Alternatively the attacker may be able to
+   exploit the algorithm vulnerability or weakness to find the shared
+   secret by reviewing the MACs from captured packets.  In either of
+   those cases, an attacker could construct a packet or packets that
+   could be inserted into an SSH stream.  To prevent that, implementors
+   are encouraged to utilize commonly accepted MAC algorithms and
+   administrators are encouraged to watch current literature and
+   discussions of cryptography to ensure that they are not using a MAC
+   algorithm that has a recently found vulnerability or weakness.
+
+   In summary, the use of this protocol without a reliable association
+   of the binding between a host and its host keys is inherently
+   insecure and is NOT RECOMMENDED.  It may however be necessary in
+   non-security critical environments, and will still provide protection
+   against passive attacks.  Implementors of protocols and applications
+   running on top of this protocol should keep this possibility in mind.
+
+9.2.5 Denial-of-service
+
+   This protocol is designed to be used over a reliable transport.  If
+   transmission errors or message manipulation occur, the connection is
+   closed.  The connection SHOULD be re-established if this occurs.
+   Denial of service attacks of this type ("wire cutter") are almost
+   impossible to avoid.
+
+   In addition, this protocol is vulnerable to Denial of Service attacks
+   because an attacker can force the server to go through the CPU and
+   memory intensive tasks of connection setup and key exchange without
+   authenticating.  Implementors SHOULD provide features that make this
+   more difficult.  For example, only allowing connections from a subset
+   of IPs known to have valid users.
+
+9.2.6 Covert Channels
+
+   The protocol was not designed to eliminate covert channels.  For
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 19]
+
+Internet-Draft         SSH Protocol Architecture                Oct 2003
+
+
+   example, the padding, SSH_MSG_IGNORE messages, and several other
+   places in the protocol can be used to pass covert information, and
+   the recipient has no reliable way to verify whether such information
+   is being sent.
+
+9.2.7 Forward Secrecy
+
+   It should be noted that the Diffie-Hellman key exchanges may provide
+   perfect forward secrecy (PFS).  PFS is essentially defined as the
+   cryptographic property of a key-establishment protocol in which the
+   compromise of a session key or long-term private key after a given
+   session does not cause the compromise of any earlier session. [ANSI
+   T1.523-2001]  SSHv2 sessions resulting from a key exchange using
+   diffie-hellman-group1-sha1 are secure even if private keying/
+   authentication material is later revealed, but not if the session
+   keys are revealed. So, given this definition of PFS, SSHv2 does have
+   PFS.  It is hoped that all other key exchange mechanisms proposed and
+   used in the future will also provide PFS.  This property is not
+   commuted to any of the applications or protocols using SSH as a
+   transport however.  The transport layer of SSH provides
+   confidentiality for password authentication and other methods that
+   rely on secret data.
+
+   Of course, if the DH private parameters for the client and server are
+   revealed then the session key is revealed, but these items can be
+   thrown away after the key exchange completes.  It's worth pointing
+   out that these items should not be allowed to end up on swap space
+   and that they should be erased from memory as soon as the key
+   exchange completes.
+
+9.3 Authentication Protocol
+
+   The purpose of this protocol is to perform client user
+   authentication. It assumes that this run over a secure transport
+   layer protocol, which has already authenticated the server machine,
+   established an encrypted communications channel, and computed a
+   unique session identifier for this session.
+
+   Several authentication methods with different security
+   characteristics are allowed.  It is up to the server's local policy
+   to decide which methods (or combinations of methods) it is willing to
+   accept for each user.  Authentication is no stronger than the weakest
+   combination allowed.
+
+   The server may go into a "sleep" period after repeated unsuccessful
+   authentication attempts to make key search more difficult for
+   attackers.  Care should be taken so that this doesn't become a
+   self-denial of service vector.
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 20]
+
+Internet-Draft         SSH Protocol Architecture                Oct 2003
+
+
+9.3.1 Weak Transport
+
+   If the transport layer does not provide confidentiality,
+   authentication methods that rely on secret data SHOULD be disabled.
+   If it does not provide strong integrity protection, requests to
+   change authentication data (e.g. a password change) SHOULD be
+   disabled to prevent an attacker from  modifying the ciphertext
+   without being noticed, or rendering the new authentication data
+   unusable (denial of service).
+
+   The assumption as stated above that the Authentication Protocol only
+   run over a secure transport that has previously authenticated the
+   server is very important to note.  People deploying SSH are reminded
+   of the consequences of man-in-the-middle attacks if the client does
+   not have a very strong a priori association of the server with the
+   host key of that server.  Specifically for the case of the
+   Authentication Protocol the client may form a session to a
+   man-in-the-middle attack device and divulge user credentials such as
+   their username and password.  Even in the cases of authentication
+   where no user credentials are divulged, an attacker may still gain
+   information they shouldn't have by capturing key-strokes in much the
+   same way that a honeypot works.
+
+9.3.2 Debug messages
+
+   Special care should be taken when designing debug messages.  These
+   messages may reveal surprising amounts of information about the host
+   if not properly designed.  Debug messages can be disabled (during
+   user authentication phase) if high security is required.
+   Administrators of host machines should make all attempts to
+   compartmentalize all event notification messages and protect them
+   from unwarranted observation.  Developers should be aware of the
+   sensitive nature of some of the normal event messages and debug
+   messages and may want to provide guidance to administrators on ways
+   to keep this information away from unauthorized people.  Developers
+   should consider minimizing the amount of sensitive information
+   obtainable by users during the authentication phase in accordance
+   with the local policies.  For this reason, it is RECOMMENDED that
+   debug messages be initially disabled at the time of deployment and
+   require an active decision by an administrator to allow them to be
+   enabled.  It is also RECOMMENDED that a message expressing this
+   concern be presented to the administrator of a system when the action
+   is taken to enable debugging messages.
+
+9.3.3 Local security policy
+
+   Implementer MUST ensure that the credentials provided validate the
+   professed user and also MUST ensure that the local policy of the
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 21]
+
+Internet-Draft         SSH Protocol Architecture                Oct 2003
+
+
+   server permits the user the access requested.  In particular, because
+   of the flexible nature of the SSH connection protocol, it may not be
+   possible to determine the local security policy, if any, that should
+   apply at the time of authentication because the kind of service being
+   requested is not clear at that instant. For example, local policy
+   might allow a user to access files on the server, but not start an
+   interactive shell. However, during the authentication protocol, it is
+   not known whether the user will be accessing files or attempting to
+   use an interactive shell, or even both.  In any event, where local
+   security policy for the server host exists, it MUST be applied and
+   enforced correctly.
+
+   Implementors are encouraged to provide a default local policy and
+   make its parameters known to administrators and users.  At the
+   discretion of the implementors, this default policy may be along the
+   lines of 'anything goes' where there are no restrictions placed upon
+   users, or it may be along the lines of 'excessively restrictive' in
+   which case the administrators will have to actively make changes to
+   this policy to meet their needs.  Alternatively, it may be some
+   attempt at providing something practical and immediately useful to
+   the administrators of the system so they don't have to put in much
+   effort to get SSH working.  Whatever choice is made MUST be applied
+   and enforced as required above.
+
+9.3.4 Public key authentication
+
+   The use of public-key authentication assumes that the client host has
+   not been compromised.  It also assumes that the private-key of the
+   server host has not been compromised.
+
+   This risk can be mitigated by the use of passphrases on private keys;
+   however, this is not an enforceable policy.  The use of smartcards,
+   or other technology to make passphrases an enforceable policy is
+   suggested.
+
+   The server could require both password and public-key authentication,
+   however, this requires the client to expose its password to the
+   server (see section on password authentication below.)
+
+9.3.5 Password authentication
+
+   The password mechanism as specified in the authentication protocol
+   assumes that the server has not been compromised.  If the server has
+   been compromised, using password authentication will reveal a valid
+   username / password combination to the attacker, which may lead to
+   further compromises.
+
+   This vulnerability can be mitigated by using an alternative form of
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 22]
+
+Internet-Draft         SSH Protocol Architecture                Oct 2003
+
+
+   authentication.  For example, public-key authentication makes no
+   assumptions about security on the server.
+
+9.3.6 Host based authentication
+
+   Host based authentication assumes that the client has not been
+   compromised.  There are no mitigating strategies, other than to use
+   host based authentication in combination with another authentication
+   method.
+
+9.4 Connection protocol
+
+9.4.1 End point security
+
+   End point security is assumed by the connection protocol.  If the
+   server has been compromised, any terminal sessions, port forwarding,
+   or systems accessed on the host are compromised.  There are no
+   mitigating factors for this.
+
+   If the client end point has been compromised, and the server fails to
+   stop the attacker at the authentication protocol, all services
+   exposed (either as subsystems or through forwarding) will be
+   vulnerable to attack.  Implementors SHOULD provide mechanisms for
+   administrators to control which services are exposed to limit the
+   vulnerability of other services.
+
+   These controls might include controlling which machines and ports can
+   be target in 'port-forwarding' operations, which users are allowed to
+   use interactive shell facilities, or which users are allowed to use
+   exposed subsystems.
+
+9.4.2 Proxy forwarding
+
+   The SSH connection protocol allows for proxy forwarding of other
+   protocols such as SNMP, POP3, and HTTP.  This may be a concern for
+   network administrators who wish to control the access of certain
+   applications by users located outside of their physical location.
+   Essentially, the forwarding of these protocols may violate site
+   specific security policies as they may be undetectably tunneled
+   through a firewall.  Implementors SHOULD provide an administrative
+   mechanism to control the proxy forwarding functionality so that site
+   specific security policies may be upheld.
+
+   In addition, a reverse proxy forwarding functionality is available,
+   which again can be used to bypass firewall controls.
+
+   As indicated above, end-point security is assumed during proxy
+   forwarding operations.  Failure of end-point security will compromise
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 23]
+
+Internet-Draft         SSH Protocol Architecture                Oct 2003
+
+
+   all data passed over proxy forwarding.
+
+9.4.3 X11 forwarding
+
+   Another form of proxy forwarding provided by the ssh connection
+   protocol is the forwarding of the X11 protocol.  If end-point
+   security has been compromised, X11 forwarding may allow attacks
+   against the X11 server.  Users and administrators should, as a matter
+   of course, use appropriate X11 security mechanisms to prevent
+   unauthorized use of the X11 server.  Implementors, administrators and
+   users who wish to further explore the security mechanisms of X11 are
+   invited to read [SCHEIFLER] and analyze previously reported problems
+   with the interactions between SSH forwarding and X11 in CERT
+   vulnerabilities VU#363181 and VU#118892 [CERT].
+
+   X11 display forwarding with SSH, by itself, is not sufficient to
+   correct well known problems with X11 security [VENEMA].  However, X11
+   display forwarding in SSHv2 (or other, secure protocols), combined
+   with actual and pseudo-displays which accept connections only over
+   local IPC mechanisms authorized by permissions or ACLs, does correct
+   many X11 security problems as long as the "none" MAC is not used.  It
+   is RECOMMENDED that X11 display implementations default to allowing
+   display opens only over local IPC.  It is RECOMMENDED that SSHv2
+   server implementations that support X11 forwarding default to
+   allowing display opens only over local IPC.  On single-user systems
+   it might be reasonable to default to allowing local display opens
+   over TCP/IP.
+
+   Implementors of the X11 forwarding protocol SHOULD implement the
+   magic cookie access checking spoofing mechanism as described in
+   [ssh-connect] as an additional mechanism to prevent unauthorized use
+   of the proxy.
+
+Normative References
+
+   [SSH-ARCH]
+              Ylonen, T., "SSH Protocol Architecture", I-D
+              draft-ietf-architecture-15.txt, Oct 2003.
+
+   [SSH-TRANS]
+              Ylonen, T., "SSH Transport Layer Protocol", I-D
+              draft-ietf-transport-17.txt, Oct 2003.
+
+   [SSH-USERAUTH]
+              Ylonen, T., "SSH Authentication Protocol", I-D
+              draft-ietf-userauth-18.txt, Oct 2003.
+
+   [SSH-CONNECT]
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 24]
+
+Internet-Draft         SSH Protocol Architecture                Oct 2003
+
+
+              Ylonen, T., "SSH Connection Protocol", I-D
+              draft-ietf-connect-18.txt, Oct 2003.
+
+   [SSH-NUMBERS]
+              Lehtinen, S. and D. Moffat, "SSH Protocol Assigned
+              Numbers", I-D draft-ietf-secsh-assignednumbers-05.txt, Oct
+              2003.
+
+   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
+              Requirement Levels", BCP 14, RFC 2119, March 1997.
+
+Informative References
+
+   [FIPS-186]
+              Federal Information Processing Standards Publication,
+              "FIPS PUB 186, Digital Signature Standard", May 1994.
+
+   [FIPS-197]
+              National Institue of Standards and Technology, "FIPS 197,
+              Specification for the Advanced Encryption Standard",
+              November 2001.
+
+   [ANSI T1.523-2001]
+              American National Standards Insitute, Inc., "Telecom
+              Glossary 2000", February 2001.
+
+   [SCHEIFLER]
+              Scheifler, R., "X Window System : The Complete Reference
+              to Xlib, X Protocol, Icccm, Xlfd, 3rd edition.", Digital
+              Press ISBN 1555580882, Feburary 1992.
+
+   [RFC0854]  Postel, J. and J. Reynolds, "Telnet Protocol
+              Specification", STD 8, RFC 854, May 1983.
+
+   [RFC0894]  Hornig, C., "Standard for the transmission of IP datagrams
+              over Ethernet networks", STD 41, RFC 894, April 1984.
+
+   [RFC1034]  Mockapetris, P., "Domain names - concepts and facilities",
+              STD 13, RFC 1034, November 1987.
+
+   [RFC1134]  Perkins, D., "Point-to-Point Protocol: A proposal for
+              multi-protocol transmission of datagrams over
+              Point-to-Point links", RFC 1134, November 1989.
+
+   [RFC1282]  Kantor, B., "BSD Rlogin", RFC 1282, December 1991.
+
+   [RFC1510]  Kohl, J. and B. Neuman, "The Kerberos Network
+              Authentication Service (V5)", RFC 1510, September 1993.
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 25]
+
+Internet-Draft         SSH Protocol Architecture                Oct 2003
+
+
+   [RFC1700]  Reynolds, J. and J. Postel, "Assigned Numbers", RFC 1700,
+              October 1994.
+
+   [RFC1750]  Eastlake, D., Crocker, S. and J. Schiller, "Randomness
+              Recommendations for Security", RFC 1750, December 1994.
+
+   [RFC3066]  Alvestrand, H., "Tags for the Identification of
+              Languages", BCP 47, RFC 3066, January 2001.
+
+   [RFC1964]  Linn, J., "The Kerberos Version 5 GSS-API Mechanism", RFC
+              1964, June 1996.
+
+   [RFC2025]  Adams, C., "The Simple Public-Key GSS-API Mechanism
+              (SPKM)", RFC 2025, October 1996.
+
+   [RFC2085]  Oehler, M. and R. Glenn, "HMAC-MD5 IP Authentication with
+              Replay Prevention", RFC 2085, February 1997.
+
+   [RFC2104]  Krawczyk, H., Bellare, M. and R. Canetti, "HMAC:
+              Keyed-Hashing for Message Authentication", RFC 2104,
+              February 1997.
+
+   [RFC2246]  Dierks, T., Allen, C., Treese, W., Karlton, P., Freier, A.
+              and P. Kocher, "The TLS Protocol Version 1.0", RFC 2246,
+              January 1999.
+
+   [RFC2279]  Yergeau, F., "UTF-8, a transformation format of ISO
+              10646", RFC 2279, January 1998.
+
+   [RFC2410]  Glenn, R. and S. Kent, "The NULL Encryption Algorithm and
+              Its Use With IPsec", RFC 2410, November 1998.
+
+   [RFC2434]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
+              IANA Considerations Section in RFCs", BCP 26, RFC 2434,
+              October 1998.
+
+   [RFC2743]  Linn, J., "Generic Security Service Application Program
+              Interface Version 2, Update 1", RFC 2743, January 2000.
+
+   [SCHNEIER]
+              Schneier, B., "Applied Cryptography Second Edition:
+              protocols algorithms and source in code in C", 1996.
+
+   [KAUFMAN,PERLMAN,SPECINER]
+              Kaufman, C., Perlman, R. and M. Speciner, "Network
+              Security: PRIVATE Communication in a PUBLIC World", 1995.
+
+   [CERT]     CERT Coordination Center, The., "http://www.cert.org/nav/
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 26]
+
+Internet-Draft         SSH Protocol Architecture                Oct 2003
+
+
+              index_red.html".
+
+   [VENEMA]   Venema, W., "Murphy's Law and Computer Security",
+              Proceedings of 6th USENIX Security Symposium, San Jose CA
+              http://www.usenix.org/publications/library/proceedings/
+              sec96/venema.html, July 1996.
+
+   [ROGAWAY]  Rogaway, P., "Problems with Proposed IP Cryptography",
+              Unpublished paper http://www.cs.ucdavis.edu/~rogaway/
+              papers/draft-rogaway-ipsec-comments-00.txt, 1996.
+
+   [DAI]      Dai, W., "An attack against SSH2 protocol", Email to the
+              SECSH Working Group [email protected] ftp://
+              ftp.ietf.org/ietf-mail-archive/secsh/2002-02.mail, Feb
+              2002.
+
+   [BELLARE,KOHNO,NAMPREMPRE]
+              Bellaire, M., Kohno, T. and C. Namprempre, "Authenticated
+              Encryption in SSH: Fixing the SSH Binary Packet Protocol",
+              , Sept 2002.
+
+
+Authors' Addresses
+
+   Tatu Ylonen
+   SSH Communications Security Corp
+   Fredrikinkatu 42
+   HELSINKI  FIN-00100
+   Finland
+
+   EMail: [email protected]
+
+
+   Darren J. Moffat (editor)
+   Sun Microsystems, Inc
+   17 Network Circle
+   Menlo Park  CA 94025
+   USA
+
+   EMail: [email protected]
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 27]
+
+Internet-Draft         SSH Protocol Architecture                Oct 2003
+
+
+Intellectual Property Statement
+
+   The IETF takes no position regarding the validity or scope of any
+   intellectual property or other rights that might be claimed to
+   pertain to the implementation or use of the technology described in
+   this document or the extent to which any license under such rights
+   might or might not be available; neither does it represent that it
+   has made any effort to identify any such rights. Information on the
+   IETF's procedures with respect to rights in standards-track and
+   standards-related documentation can be found in BCP-11. Copies of
+   claims of rights made available for publication and any assurances of
+   licenses to be made available, or the result of an attempt made to
+   obtain a general license or permission for the use of such
+   proprietary rights by implementors or users of this specification can
+   be obtained from the IETF Secretariat.
+
+   The IETF invites any interested party to bring to its attention any
+   copyrights, patents or patent applications, or other proprietary
+   rights which may cover technology that may be required to practice
+   this standard. Please address the information to the IETF Executive
+   Director.
+
+   The IETF has been notified of intellectual property rights claimed in
+   regard to some or all of the specification contained in this
+   document. For more information consult the online list of claimed
+   rights.
+
+
+Full Copyright Statement
+
+   Copyright (C) The Internet Society (2003). All Rights Reserved.
+
+   This document and translations of it may be copied and furnished to
+   others, and derivative works that comment on or otherwise explain it
+   or assist in its implementation may be prepared, copied, published
+   and distributed, in whole or in part, without restriction of any
+   kind, provided that the above copyright notice and this paragraph are
+   included on all such copies and derivative works. However, this
+   document itself may not be modified in any way, such as by removing
+   the copyright notice or references to the Internet Society or other
+   Internet organizations, except as needed for the purpose of
+   developing Internet standards in which case the procedures for
+   copyrights defined in the Internet Standards process must be
+   followed, or as required to translate it into languages other than
+   English.
+
+   The limited permissions granted above are perpetual and will not be
+   revoked by the Internet Society or its successors or assignees.
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 28]
+
+Internet-Draft         SSH Protocol Architecture                Oct 2003
+
+
+   This document and the information contained herein is provided on an
+   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
+   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
+   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
+   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
+   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+
+
+Acknowledgment
+
+   Funding for the RFC Editor function is currently provided by the
+   Internet Society.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Moffat          Expires March 31, 2004                [Page 29]
\ No newline at end of file
diff --git a/lib/ssh/doc/standard/draft-ietf-secsh-connect-18.2.ps b/lib/ssh/doc/standard/draft-ietf-secsh-connect-18.2.ps
new file mode 100644
index 0000000000..7a386724c2
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+(Network Working Group                                          T. Ylonen) s
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+(Internet-Draft                          SSH Communications Security Corp) s
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+(Expires: March 31, 2004                           D. Moffat, Editor, Ed.) s
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+(                                                   Sun Microsystems, Inc) s
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+(                                                                Oct 2003) s
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+(                        SSH Connection Protocol) s
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+(                    draft-ietf-secsh-connect-18.txt) s
+5 591 M
+(Status of this Memo) s
+5 569 M
+(   This document is an Internet-Draft and is in full conformance with) s
+5 558 M
+(   all provisions of Section 10 of RFC2026.) s
+5 536 M
+(   Internet-Drafts are working documents of the Internet Engineering) s
+5 525 M
+(   Task Force \(IETF\), its areas, and its working groups. Note that other) s
+5 514 M
+(   groups may also distribute working documents as Internet-Drafts.) s
+5 492 M
+(   Internet-Drafts are draft documents valid for a maximum of six months) s
+5 481 M
+(   and may be updated, replaced, or obsoleted by other documents at any) s
+5 470 M
+(   time. It is inappropriate to use Internet-Drafts as reference) s
+5 459 M
+(   material or to cite them other than as "work in progress.") s
+5 437 M
+(   The list of current Internet-Drafts can be accessed at http://) s
+5 426 M
+(   www.ietf.org/ietf/1id-abstracts.txt.) s
+5 404 M
+(   The list of Internet-Draft Shadow Directories can be accessed at) s
+5 393 M
+(   http://www.ietf.org/shadow.html.) s
+5 371 M
+(   This Internet-Draft will expire on March 31, 2004.) s
+5 349 M
+(Copyright Notice) s
+5 327 M
+(   Copyright \(C\) The Internet Society \(2003\). All Rights Reserved.) s
+5 305 M
+(Abstract) s
+5 283 M
+(   SSH is a protocol for secure remote login and other secure network) s
+5 272 M
+(   services over an insecure network.) s
+5 250 M
+(   This document describes the SSH Connection Protocol. It provides) s
+5 239 M
+(   interactive login sessions, remote execution of commands, forwarded) s
+5 228 M
+(   TCP/IP connections, and forwarded X11 connections. All of these) s
+5 217 M
+(   channels are multiplexed into a single encrypted tunnel.) s
+5 195 M
+(   The SSH Connection Protocol has been designed to run on top of the) s
+5 184 M
+(   SSH transport layer and user authentication protocols.) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 1]) s
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+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
+5 690 M
+(Table of Contents) s
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+(   1.    Contributors . . . . . . . . . . . . . . . . . . . . . . . .  3) s
+5 657 M
+(   2.    Introduction . . . . . . . . . . . . . . . . . . . . . . . .  3) s
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+(   3.    Conventions Used in This Document  . . . . . . . . . . . . .  3) s
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+(   4.    Global Requests  . . . . . . . . . . . . . . . . . . . . . .  3) s
+5 624 M
+(   5.    Channel Mechanism  . . . . . . . . . . . . . . . . . . . . .  4) s
+5 613 M
+(   5.1   Opening a Channel  . . . . . . . . . . . . . . . . . . . . .  4) s
+5 602 M
+(   5.2   Data Transfer  . . . . . . . . . . . . . . . . . . . . . . .  5) s
+5 591 M
+(   5.3   Closing a Channel  . . . . . . . . . . . . . . . . . . . . .  6) s
+5 580 M
+(   5.4   Channel-Specific Requests  . . . . . . . . . . . . . . . . .  7) s
+5 569 M
+(   6.    Interactive Sessions . . . . . . . . . . . . . . . . . . . .  8) s
+5 558 M
+(   6.1   Opening a Session  . . . . . . . . . . . . . . . . . . . . .  8) s
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+(   6.2   Requesting a Pseudo-Terminal . . . . . . . . . . . . . . . .  8) s
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+(   6.3   X11 Forwarding . . . . . . . . . . . . . . . . . . . . . . .  9) s
+5 525 M
+(   6.3.1 Requesting X11 Forwarding  . . . . . . . . . . . . . . . . .  9) s
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+(   6.3.2 X11 Channels . . . . . . . . . . . . . . . . . . . . . . . . 10) s
+5 503 M
+(   6.4   Environment Variable Passing . . . . . . . . . . . . . . . . 10) s
+5 492 M
+(   6.5   Starting a Shell or a Command  . . . . . . . . . . . . . . . 10) s
+5 481 M
+(   6.6   Session Data Transfer  . . . . . . . . . . . . . . . . . . . 11) s
+5 470 M
+(   6.7   Window Dimension Change Message  . . . . . . . . . . . . . . 12) s
+5 459 M
+(   6.8   Local Flow Control . . . . . . . . . . . . . . . . . . . . . 12) s
+5 448 M
+(   6.9   Signals  . . . . . . . . . . . . . . . . . . . . . . . . . . 12) s
+5 437 M
+(   6.10  Returning Exit Status  . . . . . . . . . . . . . . . . . . . 13) s
+5 426 M
+(   7.    TCP/IP Port Forwarding . . . . . . . . . . . . . . . . . . . 14) s
+5 415 M
+(   7.1   Requesting Port Forwarding . . . . . . . . . . . . . . . . . 14) s
+5 404 M
+(   7.2   TCP/IP Forwarding Channels . . . . . . . . . . . . . . . . . 15) s
+5 393 M
+(   8.    Encoding of Terminal Modes . . . . . . . . . . . . . . . . . 16) s
+5 382 M
+(   9.    Summary of Message Numbers . . . . . . . . . . . . . . . . . 18) s
+5 371 M
+(   10.   Security Considerations  . . . . . . . . . . . . . . . . . . 18) s
+5 360 M
+(   11.   iana cONSiderations  . . . . . . . . . . . . . . . . . . . . 19) s
+5 349 M
+(   12.   Intellectual Property  . . . . . . . . . . . . . . . . . . . 19) s
+5 338 M
+(         Normative References . . . . . . . . . . . . . . . . . . . . 19) s
+5 327 M
+(         Informative References . . . . . . . . . . . . . . . . . . . 20) s
+5 316 M
+(         Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 20) s
+5 305 M
+(         Intellectual Property and Copyright Statements . . . . . . . 21) s
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+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
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+(1. Contributors) s
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+(   The major original contributors of this document were: Tatu Ylonen,) s
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+(   Tero Kivinen, Timo J. Rinne, Sami Lehtinen \(all of SSH Communications) s
+5 646 M
+(   Security Corp\), and Markku-Juhani O. Saarinen \(University of) s
+5 635 M
+(   Jyvaskyla\)) s
+5 613 M
+(   The document editor is: [email protected].  Comments on this) s
+5 602 M
+(   internet draft should be sent to the IETF SECSH working group,) s
+5 591 M
+(   details at: http://ietf.org/html.charters/secsh-charter.html) s
+5 569 M
+(2. Introduction) s
+5 547 M
+(   The SSH Connection Protocol has been designed to run on top of the) s
+5 536 M
+(   SSH transport layer and user authentication protocols. It provides) s
+5 525 M
+(   interactive login sessions, remote execution of commands, forwarded) s
+5 514 M
+(   TCP/IP connections, and forwarded X11 connections. The service name) s
+5 503 M
+(   for this protocol is "ssh-connection".) s
+5 481 M
+(   This document should be read only after reading the SSH architecture) s
+5 470 M
+(   document [SSH-ARCH]. This document freely uses terminology and) s
+5 459 M
+(   notation from the architecture document without reference or further) s
+5 448 M
+(   explanation.) s
+5 426 M
+(3. Conventions Used in This Document) s
+5 404 M
+(   The keywords "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT",) s
+5 393 M
+(   and "MAY" that appear in this document are to be interpreted as) s
+5 382 M
+(   described in [RFC2119].) s
+5 360 M
+(   The used data types and terminology are specified in the architecture) s
+5 349 M
+(   document [SSH-ARCH].) s
+5 327 M
+(   The architecture document also discusses the algorithm naming) s
+5 316 M
+(   conventions that MUST be used with the SSH protocols.) s
+5 294 M
+(4. Global Requests) s
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+(   remote end "globally", independent of any channels.  An example is a) s
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+(   requests use the following format.) s
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+(     byte      SSH_MSG_GLOBAL_REQUEST) s
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+(     string    request name \(restricted to US-ASCII\)) s
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+(     boolean   want reply) s
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+(     ... request-specific data follows) s
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+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
+5 690 M
+(   Request names follow the DNS extensibility naming convention outlined) s
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+(5. Channel Mechanism) s
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+(   Either side may open a channel.  Multiple channels are multiplexed) s
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+(   into a single connection.) s
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+(   to a channel may be different on each side.  Requests to open a) s
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+(   channel contain the sender's channel number.  Any other) s
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+(   channel-related messages contain the recipient's channel number for) s
+5 382 M
+(   the channel.) s
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+(   Channels are flow-controlled.  No data may be sent to a channel until) s
+5 349 M
+(   a message is received to indicate that window space is available.) s
+5 327 M
+(5.1 Opening a Channel) s
+5 305 M
+(   When either side wishes to open a new channel, it allocates a local) s
+5 294 M
+(   number for the channel.  It then sends the following message to the) s
+5 283 M
+(   other side, and includes the local channel number and initial window) s
+5 272 M
+(   size in the message.) s
+5 250 M
+(     byte      SSH_MSG_CHANNEL_OPEN) s
+5 239 M
+(     string    channel type \(restricted to US-ASCII\)) s
+5 228 M
+(     uint32    sender channel) s
+5 217 M
+(     uint32    initial window size) s
+5 206 M
+(     uint32    maximum packet size) s
+5 195 M
+(     ... channel type specific data follows) s
+5 173 M
+(   The channel type is a name as described in the SSH architecture) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 4]) s
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+/pagenum 5 def
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+/ftail () def
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+5 723 M
+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
+5 690 M
+(   document, with similar extension mechanisms. `sender channel' is a) s
+5 679 M
+(   local identifier for the channel used by the sender of this message.) s
+5 668 M
+(   `initial window size' specifies how many bytes of channel data can be) s
+5 657 M
+(   sent to the sender of this message without adjusting the window.) s
+5 646 M
+(   `Maximum packet size' specifies the maximum size of an individual) s
+5 635 M
+(   data packet that can be sent to the sender \(for example, one might) s
+5 624 M
+(   want to use smaller packets for interactive connections to get better) s
+5 613 M
+(   interactive response on slow links\).) s
+5 591 M
+(   The remote side then decides whether it can open the channel, and) s
+5 580 M
+(   responds with either) s
+5 558 M
+(     byte      SSH_MSG_CHANNEL_OPEN_CONFIRMATION) s
+5 547 M
+(     uint32    recipient channel) s
+5 536 M
+(     uint32    sender channel) s
+5 525 M
+(     uint32    initial window size) s
+5 514 M
+(     uint32    maximum packet size) s
+5 503 M
+(     ... channel type specific data follows) s
+5 481 M
+(   where `recipient channel' is the channel number given in the original) s
+5 470 M
+(   open request, and `sender channel' is the channel number allocated by) s
+5 459 M
+(   the other side, or) s
+5 437 M
+(     byte      SSH_MSG_CHANNEL_OPEN_FAILURE) s
+5 426 M
+(     uint32    recipient channel) s
+5 415 M
+(     uint32    reason code) s
+5 404 M
+(     string    additional textual information \(ISO-10646 UTF-8 [RFC2279]\)) s
+5 393 M
+(     string    language tag \(as defined in [RFC3066]\)) s
+5 371 M
+(   If the recipient of the SSH_MSG_CHANNEL_OPEN message does not support) s
+5 360 M
+(   the specified channel type, it simply responds with) s
+5 349 M
+(   SSH_MSG_CHANNEL_OPEN_FAILURE. The client MAY show the additional) s
+5 338 M
+(   information to the user. If this is done, the client software should) s
+5 327 M
+(   take the precautions discussed in [SSH-ARCH].) s
+5 305 M
+(   The following reason codes are defined:) s
+5 283 M
+(     #define SSH_OPEN_ADMINISTRATIVELY_PROHIBITED    1) s
+5 272 M
+(     #define SSH_OPEN_CONNECT_FAILED                 2) s
+5 261 M
+(     #define SSH_OPEN_UNKNOWN_CHANNEL_TYPE           3) s
+5 250 M
+(     #define SSH_OPEN_RESOURCE_SHORTAGE              4) s
+5 217 M
+(5.2 Data Transfer) s
+5 195 M
+(   The window size specifies how many bytes the other party can send) s
+5 184 M
+(   before it must wait for the window to be adjusted.  Both parties use) s
+5 173 M
+(   the following message to adjust the window.) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 5]) s
+_R
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+/pagenum 6 def
+/fname () def
+/fdir () def
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+5 723 M
+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
+5 690 M
+(     byte      SSH_MSG_CHANNEL_WINDOW_ADJUST) s
+5 679 M
+(     uint32    recipient channel) s
+5 668 M
+(     uint32    bytes to add) s
+5 646 M
+(   After receiving this message, the recipient MAY send the given number) s
+5 635 M
+(   of bytes more than it was previously allowed to send; the window size) s
+5 624 M
+(   is incremented.) s
+5 602 M
+(   Data transfer is done with messages of the following type.) s
+5 580 M
+(     byte      SSH_MSG_CHANNEL_DATA) s
+5 569 M
+(     uint32    recipient channel) s
+5 558 M
+(     string    data) s
+5 536 M
+(   The maximum amount of data allowed is the current window size.  The) s
+5 525 M
+(   window size is decremented by the amount of data sent. Both parties) s
+5 514 M
+(   MAY ignore all extra data sent after the allowed window is empty.) s
+5 492 M
+(   Additionally, some channels can transfer several types of data.  An) s
+5 481 M
+(   example of this is stderr data from interactive sessions. Such data) s
+5 470 M
+(   can be passed with SSH_MSG_CHANNEL_EXTENDED_DATA messages, where a) s
+5 459 M
+(   separate integer specifies the type of the data.  The available types) s
+5 448 M
+(   and their interpretation depend on the type of the channel.) s
+5 426 M
+(     byte      SSH_MSG_CHANNEL_EXTENDED_DATA) s
+5 415 M
+(     uint32    recipient_channel) s
+5 404 M
+(     uint32    data_type_code) s
+5 393 M
+(     string    data) s
+5 371 M
+(   Data sent with these messages consumes the same window as ordinary) s
+5 360 M
+(   data.) s
+5 338 M
+(   Currently, only the following type is defined.) s
+5 316 M
+(   #define SSH_EXTENDED_DATA_STDERR                1) s
+5 283 M
+(5.3 Closing a Channel) s
+5 261 M
+(   When a party will no longer send more data to a channel, it SHOULD) s
+5 250 M
+(   send SSH_MSG_CHANNEL_EOF.) s
+5 228 M
+(     byte      SSH_MSG_CHANNEL_EOF) s
+5 217 M
+(     uint32    recipient_channel) s
+5 195 M
+(   No explicit response is sent to this message; however, the) s
+5 184 M
+(   application may send EOF to whatever is at the other end of the) s
+5 173 M
+(   channel.  Note that the channel remains open after this message, and) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 6]) s
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+/showpage{}def/copypage{}def/erasepage{}def
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+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 7 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
+5 690 M
+(   more data may still be sent in the other direction.  This message) s
+5 679 M
+(   does not consume window space and can be sent even if no window space) s
+5 668 M
+(   is available.) s
+5 646 M
+(   When either party wishes to terminate the channel, it sends) s
+5 635 M
+(   SSH_MSG_CHANNEL_CLOSE.  Upon receiving this message, a party MUST) s
+5 624 M
+(   send back a SSH_MSG_CHANNEL_CLOSE unless it has already sent this) s
+5 613 M
+(   message for the channel.  The channel is considered closed for a) s
+5 602 M
+(   party when it has both sent and received SSH_MSG_CHANNEL_CLOSE, and) s
+5 591 M
+(   the party may then reuse the channel number.  A party MAY send) s
+5 580 M
+(   SSH_MSG_CHANNEL_CLOSE without having sent or received) s
+5 569 M
+(   SSH_MSG_CHANNEL_EOF.) s
+5 547 M
+(     byte      SSH_MSG_CHANNEL_CLOSE) s
+5 536 M
+(     uint32    recipient_channel) s
+5 514 M
+(   This message does not consume window space and can be sent even if no) s
+5 503 M
+(   window space is available.) s
+5 481 M
+(   It is recommended that any data sent before this message is delivered) s
+5 470 M
+(   to the actual destination, if possible.) s
+5 448 M
+(5.4 Channel-Specific Requests) s
+5 426 M
+(   Many channel types have extensions that are specific to that) s
+5 415 M
+(   particular channel type.  An example is requesting a pty \(pseudo) s
+5 404 M
+(   terminal\) for an interactive session.) s
+5 382 M
+(   All channel-specific requests use the following format.) s
+5 360 M
+(     byte      SSH_MSG_CHANNEL_REQUEST) s
+5 349 M
+(     uint32    recipient channel) s
+5 338 M
+(     string    request type \(restricted to US-ASCII\)) s
+5 327 M
+(     boolean   want reply) s
+5 316 M
+(     ... type-specific data) s
+5 294 M
+(   If want reply is FALSE, no response will be sent to the request.) s
+5 283 M
+(   Otherwise, the recipient responds with either SSH_MSG_CHANNEL_SUCCESS) s
+5 272 M
+(   or SSH_MSG_CHANNEL_FAILURE, or request-specific continuation) s
+5 261 M
+(   messages. If the request is not recognized or is not supported for) s
+5 250 M
+(   the channel, SSH_MSG_CHANNEL_FAILURE is returned.) s
+5 228 M
+(   This message does not consume window space and can be sent even if no) s
+5 217 M
+(   window space is available. Request types are local to each channel) s
+5 206 M
+(   type.) s
+5 184 M
+(   The client is allowed to send further messages without waiting for) s
+5 173 M
+(   the response to the request.) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 7]) s
+_R
+S
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+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
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+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 8 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
+5 690 M
+(   request type names follow the DNS extensibility naming convention) s
+5 679 M
+(   outlined in [SSH-ARCH]) s
+5 657 M
+(     byte      SSH_MSG_CHANNEL_SUCCESS) s
+5 646 M
+(     uint32    recipient_channel) s
+5 613 M
+(     byte      SSH_MSG_CHANNEL_FAILURE) s
+5 602 M
+(     uint32    recipient_channel) s
+5 580 M
+(   These messages do not consume window space and can be sent even if no) s
+5 569 M
+(   window space is available.) s
+5 547 M
+(6. Interactive Sessions) s
+5 525 M
+(   A session is a remote execution of a program.  The program may be a) s
+5 514 M
+(   shell, an application, a system command, or some built-in subsystem.) s
+5 503 M
+(   It may or may not have a tty, and may or may not involve X11) s
+5 492 M
+(   forwarding. Multiple sessions can be active simultaneously.) s
+5 470 M
+(6.1 Opening a Session) s
+5 448 M
+(   A session is started by sending the following message.) s
+5 426 M
+(     byte      SSH_MSG_CHANNEL_OPEN) s
+5 415 M
+(     string    "session") s
+5 404 M
+(     uint32    sender channel) s
+5 393 M
+(     uint32    initial window size) s
+5 382 M
+(     uint32    maximum packet size) s
+5 360 M
+(   Client implementations SHOULD reject any session channel open) s
+5 349 M
+(   requests to make it more difficult for a corrupt server to attack the) s
+5 338 M
+(   client.) s
+5 316 M
+(6.2 Requesting a Pseudo-Terminal) s
+5 294 M
+(   A pseudo-terminal can be allocated for the session by sending the) s
+5 283 M
+(   following message.) s
+5 261 M
+(     byte      SSH_MSG_CHANNEL_REQUEST) s
+5 250 M
+(     uint32    recipient_channel) s
+5 239 M
+(     string    "pty-req") s
+5 228 M
+(     boolean   want_reply) s
+5 217 M
+(     string    TERM environment variable value \(e.g., vt100\)) s
+5 206 M
+(     uint32    terminal width, characters \(e.g., 80\)) s
+5 195 M
+(     uint32    terminal height, rows \(e.g., 24\)) s
+5 184 M
+(     uint32    terminal width, pixels \(e.g., 640\)) s
+5 173 M
+(     uint32    terminal height, pixels \(e.g., 480\)) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 8]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (8,9) 5
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+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
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+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
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+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 9 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
+5 690 M
+(     string    encoded terminal modes) s
+5 668 M
+(   The encoding of terminal modes is described in Section Encoding of) s
+5 657 M
+(   Terminal Modes \(Section 8\). Zero dimension parameters MUST be) s
+5 646 M
+(   ignored. The character/row dimensions override the pixel dimensions) s
+5 635 M
+(   \(when nonzero\). Pixel dimensions refer to the drawable area of the) s
+5 624 M
+(   window.) s
+5 602 M
+(   The dimension parameters are only informational.) s
+5 580 M
+(   The client SHOULD ignore pty requests.) s
+5 558 M
+(6.3 X11 Forwarding) s
+5 536 M
+(6.3.1 Requesting X11 Forwarding) s
+5 514 M
+(   X11 forwarding may be requested for a session by sending) s
+5 492 M
+(     byte      SSH_MSG_CHANNEL_REQUEST) s
+5 481 M
+(     uint32    recipient channel) s
+5 470 M
+(     string    "x11-req") s
+5 459 M
+(     boolean   want reply) s
+5 448 M
+(     boolean   single connection) s
+5 437 M
+(     string    x11 authentication protocol) s
+5 426 M
+(     string    x11 authentication cookie) s
+5 415 M
+(     uint32    x11 screen number) s
+5 393 M
+(   It is recommended that the authentication cookie that is sent be a) s
+5 382 M
+(   fake, random cookie, and that the cookie is checked and replaced by) s
+5 371 M
+(   the real cookie when a connection request is received.) s
+5 349 M
+(   X11 connection forwarding should stop when the session channel is) s
+5 338 M
+(   closed; however, already opened forwardings should not be) s
+5 327 M
+(   automatically closed when the session channel is closed.) s
+5 305 M
+(   If `single connection' is TRUE, only a single connection should be) s
+5 294 M
+(   forwarded.  No more connections will be forwarded after the first, or) s
+5 283 M
+(   after the session channel has been closed.) s
+5 261 M
+(   The "x11 authentication protocol" is the name of the X11) s
+5 250 M
+(   authentication method used, e.g. "MIT-MAGIC-COOKIE-1".) s
+5 228 M
+(   The x11 authentication cookie MUST be hexadecimal encoded.) s
+5 206 M
+(   X Protocol is documented in [SCHEIFLER].) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 9]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
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+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 10 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
+5 690 M
+(6.3.2 X11 Channels) s
+5 668 M
+(   X11 channels are opened with a channel open request.  The resulting) s
+5 657 M
+(   channels are independent of the session, and closing the session) s
+5 646 M
+(   channel does not close the forwarded X11 channels.) s
+5 624 M
+(     byte      SSH_MSG_CHANNEL_OPEN) s
+5 613 M
+(     string    "x11") s
+5 602 M
+(     uint32    sender channel) s
+5 591 M
+(     uint32    initial window size) s
+5 580 M
+(     uint32    maximum packet size) s
+5 569 M
+(     string    originator address \(e.g. "192.168.7.38"\)) s
+5 558 M
+(     uint32    originator port) s
+5 536 M
+(   The recipient should respond with SSH_MSG_CHANNEL_OPEN_CONFIRMATION) s
+5 525 M
+(   or SSH_MSG_CHANNEL_OPEN_FAILURE.) s
+5 503 M
+(   Implementations MUST reject any X11 channel open requests if they) s
+5 492 M
+(   have not requested X11 forwarding.) s
+5 470 M
+(6.4 Environment Variable Passing) s
+5 448 M
+(   Environment variables may be passed to the shell/command to be) s
+5 437 M
+(   started later. Uncontrolled setting of environment variables in a) s
+5 426 M
+(   privileged process can be a security hazard.  It is recommended that) s
+5 415 M
+(   implementations either maintain a list of allowable variable names or) s
+5 404 M
+(   only set environment variables after the server process has dropped) s
+5 393 M
+(   sufficient privileges.) s
+5 371 M
+(     byte      SSH_MSG_CHANNEL_REQUEST) s
+5 360 M
+(     uint32    recipient channel) s
+5 349 M
+(     string    "env") s
+5 338 M
+(     boolean   want reply) s
+5 327 M
+(     string    variable name) s
+5 316 M
+(     string    variable value) s
+5 283 M
+(6.5 Starting a Shell or a Command) s
+5 261 M
+(   Once the session has been set up, a program is started at the remote) s
+5 250 M
+(   end. The program can be a shell, an application program or a) s
+5 239 M
+(   subsystem with a host-independent name.  Only one of these requests) s
+5 228 M
+(   can succeed per channel.) s
+5 206 M
+(     byte      SSH_MSG_CHANNEL_REQUEST) s
+5 195 M
+(     uint32    recipient channel) s
+5 184 M
+(     string    "shell") s
+5 173 M
+(     boolean   want reply) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 10]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (10,11) 6
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+0.706651 dup scale
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+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 11 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
+5 690 M
+(   This message will request the user's default shell \(typically defined) s
+5 679 M
+(   in /etc/passwd in UNIX systems\) to be started at the other end.) s
+5 657 M
+(     byte      SSH_MSG_CHANNEL_REQUEST) s
+5 646 M
+(     uint32    recipient channel) s
+5 635 M
+(     string    "exec") s
+5 624 M
+(     boolean   want reply) s
+5 613 M
+(     string    command) s
+5 591 M
+(   This message will request the server to start the execution of the) s
+5 580 M
+(   given command. The command string may contain a path. Normal) s
+5 569 M
+(   precautions MUST be taken to prevent the execution of unauthorized) s
+5 558 M
+(   commands.) s
+5 536 M
+(     byte      SSH_MSG_CHANNEL_REQUEST) s
+5 525 M
+(     uint32    recipient channel) s
+5 514 M
+(     string    "subsystem") s
+5 503 M
+(     boolean   want reply) s
+5 492 M
+(     string    subsystem name) s
+5 470 M
+(   This last form executes a predefined subsystem.  It is expected that) s
+5 459 M
+(   these will include a general file transfer mechanism, and possibly) s
+5 448 M
+(   other features.  Implementations may also allow configuring more such) s
+5 437 M
+(   mechanisms. As the user's shell is usually used to execute the) s
+5 426 M
+(   subsystem, it is advisable for the subsystem protocol to have a) s
+5 415 M
+(   "magic cookie" at the beginning of the protocol transaction to) s
+5 404 M
+(   distinguish it from arbitrary output generated by shell) s
+5 393 M
+(   initialization scripts etc. This spurious output from the shell may) s
+5 382 M
+(   be filtered out either at the server or at the client.) s
+5 360 M
+(   The server SHOULD not halt the execution of the protocol stack when) s
+5 349 M
+(   starting a shell or a program. All input and output from these SHOULD) s
+5 338 M
+(   be redirected to the channel or to the encrypted tunnel.) s
+5 316 M
+(   It is RECOMMENDED to request and check the reply for these messages.) s
+5 305 M
+(   The client SHOULD ignore these messages.) s
+5 283 M
+(   Subsystem names follow the DNS extensibility naming convention) s
+5 272 M
+(   outlined in [SSH-ARCH].) s
+5 250 M
+(6.6 Session Data Transfer) s
+5 228 M
+(   Data transfer for a session is done using SSH_MSG_CHANNEL_DATA and) s
+5 217 M
+(   SSH_MSG_CHANNEL_EXTENDED_DATA packets and the window mechanism.  The) s
+5 206 M
+(   extended data type SSH_EXTENDED_DATA_STDERR has been defined for) s
+5 195 M
+(   stderr data.) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 11]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
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+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 12 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
+5 690 M
+(6.7 Window Dimension Change Message) s
+5 668 M
+(   When the window \(terminal\) size changes on the client side, it MAY) s
+5 657 M
+(   send a message to the other side to inform it of the new dimensions.) s
+5 635 M
+(     byte      SSH_MSG_CHANNEL_REQUEST) s
+5 624 M
+(     uint32    recipient_channel) s
+5 613 M
+(     string    "window-change") s
+5 602 M
+(     boolean   FALSE) s
+5 591 M
+(     uint32    terminal width, columns) s
+5 580 M
+(     uint32    terminal height, rows) s
+5 569 M
+(     uint32    terminal width, pixels) s
+5 558 M
+(     uint32    terminal height, pixels) s
+5 536 M
+(    No response SHOULD be sent to this message.) s
+5 514 M
+(6.8 Local Flow Control) s
+5 492 M
+(   On many systems, it is possible to determine if a pseudo-terminal is) s
+5 481 M
+(   using control-S/control-Q flow control.  When flow control is) s
+5 470 M
+(   allowed, it is often desirable to do the flow control at the client) s
+5 459 M
+(   end to speed up responses to user requests.  This is facilitated by) s
+5 448 M
+(   the following notification.  Initially, the server is responsible for) s
+5 437 M
+(   flow control. \(Here, again, client means the side originating the) s
+5 426 M
+(   session, and server means the other side.\)) s
+5 404 M
+(   The message below is used by the server to inform the client when it) s
+5 393 M
+(   can or cannot perform flow control \(control-S/control-Q processing\).) s
+5 382 M
+(   If `client can do' is TRUE, the client is allowed to do flow control) s
+5 371 M
+(   using control-S and control-Q.  The client MAY ignore this message.) s
+5 349 M
+(     byte      SSH_MSG_CHANNEL_REQUEST) s
+5 338 M
+(     uint32    recipient channel) s
+5 327 M
+(     string    "xon-xoff") s
+5 316 M
+(     boolean   FALSE) s
+5 305 M
+(     boolean   client can do) s
+5 283 M
+(   No response is sent to this message.) s
+5 261 M
+(6.9 Signals) s
+5 239 M
+(   A signal can be delivered to the remote process/service using the) s
+5 228 M
+(   following message.  Some systems may not implement signals, in which) s
+5 217 M
+(   case they SHOULD ignore this message.) s
+5 195 M
+(     byte      SSH_MSG_CHANNEL_REQUEST) s
+5 184 M
+(     uint32    recipient channel) s
+5 173 M
+(     string    "signal") s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 12]) s
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+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
+5 690 M
+(     boolean   FALSE) s
+5 679 M
+(     string    signal name without the "SIG" prefix.) s
+5 657 M
+(   Signal names will be encoded as discussed in the "exit-signal") s
+5 646 M
+(   SSH_MSG_CHANNEL_REQUEST.) s
+5 624 M
+(6.10 Returning Exit Status) s
+5 602 M
+(   When the command running at the other end terminates, the following) s
+5 591 M
+(   message can be sent to return the exit status of the command.) s
+5 580 M
+(   Returning the status is RECOMMENDED.  No acknowledgment is sent for) s
+5 569 M
+(   this message.  The channel needs to be closed with) s
+5 558 M
+(   SSH_MSG_CHANNEL_CLOSE after this message.) s
+5 536 M
+(   The client MAY ignore these messages.) s
+5 514 M
+(     byte      SSH_MSG_CHANNEL_REQUEST) s
+5 503 M
+(     uint32    recipient_channel) s
+5 492 M
+(     string    "exit-status") s
+5 481 M
+(     boolean   FALSE) s
+5 470 M
+(     uint32    exit_status) s
+5 448 M
+(   The remote command may also terminate violently due to a signal.) s
+5 437 M
+(   Such a condition can be indicated by the following message. A zero) s
+5 426 M
+(   exit_status usually means that the command terminated successfully.) s
+5 404 M
+(     byte      SSH_MSG_CHANNEL_REQUEST) s
+5 393 M
+(     uint32    recipient channel) s
+5 382 M
+(     string    "exit-signal") s
+5 371 M
+(     boolean   FALSE) s
+5 360 M
+(     string    signal name without the "SIG" prefix.) s
+5 349 M
+(     boolean   core dumped) s
+5 338 M
+(     string    error message \(ISO-10646 UTF-8\)) s
+5 327 M
+(     string    language tag \(as defined in [RFC3066]\)) s
+5 305 M
+(   The signal name is one of the following \(these are from [POSIX]\)) s
+5 283 M
+(     ABRT) s
+5 272 M
+(     ALRM) s
+5 261 M
+(     FPE) s
+5 250 M
+(     HUP) s
+5 239 M
+(     ILL) s
+5 228 M
+(     INT) s
+5 217 M
+(     KILL) s
+5 206 M
+(     PIPE) s
+5 195 M
+(     QUIT) s
+5 184 M
+(     SEGV) s
+5 173 M
+(     TERM) s
+5 129 M
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+5 723 M
+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
+5 690 M
+(     USR1) s
+5 679 M
+(     USR2) s
+5 657 M
+(   Additional signal names MAY be sent in the format "sig-name@xyz",) s
+5 646 M
+(   where `sig-name' and `xyz' may be anything a particular implementor) s
+5 635 M
+(   wants \(except the `@' sign\). However, it is suggested that if a) s
+5 624 M
+(   `configure' script is used, the non-standard signal names it finds be) s
+5 613 M
+(   encoded as "[email protected]", where `SIG' is the signal name) s
+5 602 M
+(   without the "SIG" prefix, and `xyz' be the host type, as determined) s
+5 591 M
+(   by `config.guess'.) s
+5 569 M
+(   The `error message' contains an additional explanation of the error) s
+5 558 M
+(   message. The message may consist of multiple lines. The client) s
+5 547 M
+(   software MAY display this message to the user. If this is done, the) s
+5 536 M
+(   client software should take the precautions discussed in [SSH-ARCH].) s
+5 514 M
+(7. TCP/IP Port Forwarding) s
+5 492 M
+(7.1 Requesting Port Forwarding) s
+5 470 M
+(   A party need not explicitly request forwardings from its own end to) s
+5 459 M
+(   the other direction.  However, if it wishes that connections to a) s
+5 448 M
+(   port on the other side be forwarded to the local side, it must) s
+5 437 M
+(   explicitly request this.) s
+5 404 M
+(     byte      SSH_MSG_GLOBAL_REQUEST) s
+5 393 M
+(     string    "tcpip-forward") s
+5 382 M
+(     boolean   want reply) s
+5 371 M
+(     string    address to bind \(e.g. "0.0.0.0"\)) s
+5 360 M
+(     uint32    port number to bind) s
+5 338 M
+(   `Address to bind' and `port number to bind' specify the IP address) s
+5 327 M
+(   and port to which the socket to be listened is bound.  The address) s
+5 316 M
+(   should be "0.0.0.0" if connections are allowed from anywhere. \(Note) s
+5 305 M
+(   that the client can still filter connections based on information) s
+5 294 M
+(   passed in the open request.\)) s
+5 272 M
+(   Implementations should only allow forwarding privileged ports if the) s
+5 261 M
+(   user has been authenticated as a privileged user.) s
+5 239 M
+(   Client implementations SHOULD reject these messages; they are) s
+5 228 M
+(   normally only sent by the client.) s
+5 195 M
+(   If a client passes 0 as port number to bind and has want reply TRUE) s
+5 184 M
+(   then the server allocates the next available unprivileged port number) s
+5 173 M
+(   and replies with the following message, otherwise there is no) s
+5 129 M
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+5 723 M
+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
+5 690 M
+(   response specific data.) s
+5 657 M
+(     byte     SSH_MSG_GLOBAL_REQUEST_SUCCESS) s
+5 646 M
+(     uint32   port that was bound on the server) s
+5 624 M
+(   A port forwarding can be cancelled with the following message.  Note) s
+5 613 M
+(   that channel open requests may be received until a reply to this) s
+5 602 M
+(   message is received.) s
+5 580 M
+(     byte      SSH_MSG_GLOBAL_REQUEST) s
+5 569 M
+(     string    "cancel-tcpip-forward") s
+5 558 M
+(     boolean   want reply) s
+5 547 M
+(     string    address_to_bind \(e.g. "127.0.0.1"\)) s
+5 536 M
+(     uint32    port number to bind) s
+5 514 M
+(   Client implementations SHOULD reject these messages; they are) s
+5 503 M
+(   normally only sent by the client.) s
+5 481 M
+(7.2 TCP/IP Forwarding Channels) s
+5 459 M
+(   When a connection comes to a port for which remote forwarding has) s
+5 448 M
+(   been requested, a channel is opened to forward the port to the other) s
+5 437 M
+(   side.) s
+5 415 M
+(     byte      SSH_MSG_CHANNEL_OPEN) s
+5 404 M
+(     string    "forwarded-tcpip") s
+5 393 M
+(     uint32    sender channel) s
+5 382 M
+(     uint32    initial window size) s
+5 371 M
+(     uint32    maximum packet size) s
+5 360 M
+(     string    address that was connected) s
+5 349 M
+(     uint32    port that was connected) s
+5 338 M
+(     string    originator IP address) s
+5 327 M
+(     uint32    originator port) s
+5 305 M
+(   Implementations MUST reject these messages unless they have) s
+5 294 M
+(   previously requested a remote TCP/IP port forwarding with the given) s
+5 283 M
+(   port number.) s
+5 261 M
+(   When a connection comes to a locally forwarded TCP/IP port, the) s
+5 250 M
+(   following packet is sent to the other side.  Note that these messages) s
+5 239 M
+(   MAY be sent also for ports for which no forwarding has been) s
+5 228 M
+(   explicitly requested.  The receiving side must decide whether to) s
+5 217 M
+(   allow the forwarding.) s
+5 195 M
+(     byte      SSH_MSG_CHANNEL_OPEN) s
+5 184 M
+(     string    "direct-tcpip") s
+5 173 M
+(     uint32    sender channel) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 15]) s
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+/fname () def
+/fdir () def
+/ftail () def
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+5 723 M
+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
+5 690 M
+(     uint32    initial window size) s
+5 679 M
+(     uint32    maximum packet size) s
+5 668 M
+(     string    host to connect) s
+5 657 M
+(     uint32    port to connect) s
+5 646 M
+(     string    originator IP address) s
+5 635 M
+(     uint32    originator port) s
+5 613 M
+(   `Host to connect' and `port to connect' specify the TCP/IP host and) s
+5 602 M
+(   port where the recipient should connect the channel. `Host to) s
+5 591 M
+(   connect' may be either a domain name or a numeric IP address.) s
+5 569 M
+(   `Originator IP address' is the numeric IP address of the machine) s
+5 558 M
+(   where the connection request comes from, and `originator port' is the) s
+5 547 M
+(   port on the originator host from where the connection came from.) s
+5 525 M
+(   Forwarded TCP/IP channels are independent of any sessions, and) s
+5 514 M
+(   closing a session channel does not in any way imply that forwarded) s
+5 503 M
+(   connections should be closed.) s
+5 481 M
+(   Client implementations SHOULD reject direct TCP/IP open requests for) s
+5 470 M
+(   security reasons.) s
+5 448 M
+(8. Encoding of Terminal Modes) s
+5 426 M
+(   Terminal modes \(as passed in a pty request\) are encoded into a byte) s
+5 415 M
+(   stream.  It is intended that the coding be portable across different) s
+5 404 M
+(   environments.) s
+5 382 M
+(   The tty mode description is a stream of bytes.  The stream consists) s
+5 371 M
+(   of opcode-argument pairs.  It is terminated by opcode TTY_OP_END \(0\).) s
+5 360 M
+(   Opcodes 1 to 159 have a single uint32 argument. Opcodes 160 to 255) s
+5 349 M
+(   are not yet defined, and cause parsing to stop \(they should only be) s
+5 338 M
+(   used after any other data\).) s
+5 316 M
+(   The client SHOULD put in the stream any modes it knows about, and the) s
+5 305 M
+(   server MAY ignore any modes it does not know about.  This allows some) s
+5 294 M
+(   degree of machine-independence, at least between systems that use a) s
+5 283 M
+(   POSIX-like tty interface.  The protocol can support other systems as) s
+5 272 M
+(   well, but the client may need to fill reasonable values for a number) s
+5 261 M
+(   of parameters so the server pty gets set to a reasonable mode \(the) s
+5 250 M
+(   server leaves all unspecified mode bits in their default values, and) s
+5 239 M
+(   only some combinations make sense\).) s
+5 217 M
+(   The following opcodes have been defined.  The naming of opcodes) s
+5 206 M
+(   mostly follows the POSIX terminal mode flags.) s
+5 184 M
+(   0   TTY_OP_END     Indicates end of options.) s
+5 173 M
+(   1   VINTR          Interrupt character; 255 if none.  Similarly for the) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 16]) s
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+%%BeginPageSetup
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+/fname () def
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+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
+5 690 M
+(                      other characters. Not all of these characters are) s
+5 679 M
+(                      supported on all systems.) s
+5 668 M
+(   2   VQUIT          The quit character \(sends SIGQUIT signal on POSIX) s
+5 657 M
+(                      systems\).) s
+5 646 M
+(   3   VERASE         Erase the character to left of the cursor.) s
+5 635 M
+(   4   VKILL          Kill the current input line.) s
+5 624 M
+(   5   VEOF           End-of-file character \(sends EOF from the terminal\).) s
+5 613 M
+(   6   VEOL           End-of-line character in addition to carriage return) s
+5 602 M
+(                      and/or linefeed.) s
+5 591 M
+(   7   VEOL2          Additional end-of-line character.) s
+5 580 M
+(   8   VSTART         Continues paused output \(normally control-Q\).) s
+5 569 M
+(   9   VSTOP          Pauses output \(normally control-S\).) s
+5 558 M
+(   10  VSUSP          Suspends the current program.) s
+5 547 M
+(   11  VDSUSP         Another suspend character.) s
+5 536 M
+(   12  VREPRINT       Reprints the current input line.) s
+5 525 M
+(   13  VWERASE        Erases a word left of cursor.) s
+5 514 M
+(   14  VLNEXT         Enter the next character typed literally, even if it) s
+5 503 M
+(                      is a special character) s
+5 492 M
+(   15  VFLUSH         Character to flush output.) s
+5 481 M
+(   16  VSWTCH         Switch to a different shell layer.) s
+5 470 M
+(   17  VSTATUS        Prints system status line \(load, command, pid etc\).) s
+5 459 M
+(   18  VDISCARD       Toggles the flushing of terminal output.) s
+5 448 M
+(   30  IGNPAR         The ignore parity flag.  The parameter SHOULD be 0 if) s
+5 437 M
+(                      this flag is FALSE set, and 1 if it is TRUE.) s
+5 426 M
+(   31  PARMRK         Mark parity and framing errors.) s
+5 415 M
+(   32  INPCK          Enable checking of parity errors.) s
+5 404 M
+(   33  ISTRIP         Strip 8th bit off characters.) s
+5 393 M
+(   34  INLCR          Map NL into CR on input.) s
+5 382 M
+(   35  IGNCR          Ignore CR on input.) s
+5 371 M
+(   36  ICRNL          Map CR to NL on input.) s
+5 360 M
+(   37  IUCLC          Translate uppercase characters to lowercase.) s
+5 349 M
+(   38  IXON           Enable output flow control.) s
+5 338 M
+(   39  IXANY          Any char will restart after stop.) s
+5 327 M
+(   40  IXOFF          Enable input flow control.) s
+5 316 M
+(   41  IMAXBEL        Ring bell on input queue full.) s
+5 305 M
+(   50  ISIG           Enable signals INTR, QUIT, [D]SUSP.) s
+5 294 M
+(   51  ICANON         Canonicalize input lines.) s
+5 283 M
+(   52  XCASE          Enable input and output of uppercase characters by) s
+5 272 M
+(                      preceding their lowercase equivalents with `\\'.) s
+5 261 M
+(   53  ECHO           Enable echoing.) s
+5 250 M
+(   54  ECHOE          Visually erase chars.) s
+5 239 M
+(   55  ECHOK          Kill character discards current line.) s
+5 228 M
+(   56  ECHONL         Echo NL even if ECHO is off.) s
+5 217 M
+(   57  NOFLSH         Don't flush after interrupt.) s
+5 206 M
+(   58  TOSTOP         Stop background jobs from output.) s
+5 195 M
+(   59  IEXTEN         Enable extensions.) s
+5 184 M
+(   60  ECHOCTL        Echo control characters as ^\(Char\).) s
+5 173 M
+(   61  ECHOKE         Visual erase for line kill.) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 17]) s
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+/fname () def
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+/ftail () def
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+5 723 M
+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
+5 690 M
+(   62  PENDIN         Retype pending input.) s
+5 679 M
+(   70  OPOST          Enable output processing.) s
+5 668 M
+(   71  OLCUC          Convert lowercase to uppercase.) s
+5 657 M
+(   72  ONLCR          Map NL to CR-NL.) s
+5 646 M
+(   73  OCRNL          Translate carriage return to newline \(output\).) s
+5 635 M
+(   74  ONOCR          Translate newline to carriage return-newline) s
+5 624 M
+(                      \(output\).) s
+5 613 M
+(   75  ONLRET         Newline performs a carriage return \(output\).) s
+5 602 M
+(   90  CS7            7 bit mode.) s
+5 591 M
+(   91  CS8            8 bit mode.) s
+5 580 M
+(   92  PARENB         Parity enable.) s
+5 569 M
+(   93  PARODD         Odd parity, else even.) s
+5 547 M
+(   128 TTY_OP_ISPEED  Specifies the input baud rate in bits per second.) s
+5 536 M
+(   129 TTY_OP_OSPEED  Specifies the output baud rate in bits per second.) s
+5 503 M
+(9. Summary of Message Numbers) s
+5 481 M
+(     #define SSH_MSG_GLOBAL_REQUEST                  80) s
+5 470 M
+(     #define SSH_MSG_REQUEST_SUCCESS                 81) s
+5 459 M
+(     #define SSH_MSG_REQUEST_FAILURE                 82) s
+5 448 M
+(     #define SSH_MSG_CHANNEL_OPEN                    90) s
+5 437 M
+(     #define SSH_MSG_CHANNEL_OPEN_CONFIRMATION       91) s
+5 426 M
+(     #define SSH_MSG_CHANNEL_OPEN_FAILURE            92) s
+5 415 M
+(     #define SSH_MSG_CHANNEL_WINDOW_ADJUST           93) s
+5 404 M
+(     #define SSH_MSG_CHANNEL_DATA                    94) s
+5 393 M
+(     #define SSH_MSG_CHANNEL_EXTENDED_DATA           95) s
+5 382 M
+(     #define SSH_MSG_CHANNEL_EOF                     96) s
+5 371 M
+(     #define SSH_MSG_CHANNEL_CLOSE                   97) s
+5 360 M
+(     #define SSH_MSG_CHANNEL_REQUEST                 98) s
+5 349 M
+(     #define SSH_MSG_CHANNEL_SUCCESS                 99) s
+5 338 M
+(     #define SSH_MSG_CHANNEL_FAILURE                 100) s
+5 305 M
+(10. Security Considerations) s
+5 283 M
+(   This protocol is assumed to run on top of a secure, authenticated) s
+5 272 M
+(   transport.  User authentication and protection against network-level) s
+5 261 M
+(   attacks are assumed to be provided by the underlying protocols.) s
+5 239 M
+(   It is RECOMMENDED that implementations disable all the potentially) s
+5 228 M
+(   dangerous features \(e.g. agent forwarding, X11 forwarding, and TCP/IP) s
+5 217 M
+(   forwarding\) if the host key has changed.) s
+5 195 M
+(   Full security considerations for this protocol are provided in) s
+5 184 M
+(   Section 8 of [SSH-ARCH]) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 18]) s
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+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
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+5 723 M
+(Internet-Draft          SSH Connection Protocol                 Oct 2003) s
+5 690 M
+(11. iana cONSiderations) s
+5 668 M
+(   This document is part of a set, the IANA considerations for the SSH) s
+5 657 M
+(   protocol as defined in [SSH-ARCH], [SSH-TRANS], [SSH-USERAUTH],) s
+5 646 M
+(   [SSH-CONNECT] are detailed in [SSH-NUMBERS].) s
+5 624 M
+(12. Intellectual Property) s
+5 602 M
+(   The IETF takes no position regarding the validity or scope of any) s
+5 591 M
+(   intellectual property or other rights that might be claimed to) s
+5 580 M
+(   pertain to the implementation or use of the technology described in) s
+5 569 M
+(   this document or the extent to which any license under such rights) s
+5 558 M
+(   might or might not be available; neither does it represent that it) s
+5 547 M
+(   has made any effort to identify any such rights. Information on the) s
+5 536 M
+(   IETF's procedures with respect to rights in standards-track and) s
+5 525 M
+(   standards-related documentation can be found in BCP-11. Copies of) s
+5 514 M
+(   claims of rights made available for publication and any assurances of) s
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+(   licenses to be made available, or the result of an attempt made to) s
+5 492 M
+(   obtain a general license or permission for the use of such) s
+5 481 M
+(   proprietary rights by implementers or users of this specification can) s
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+(   be obtained from the IETF Secretariat.) s
+5 448 M
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+5 437 M
+(   regard to some or all of the specification contained in this) s
+5 426 M
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+5 415 M
+(   rights.) s
+5 393 M
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+5 371 M
+(   [SSH-ARCH]) s
+5 360 M
+(              Ylonen, T., "SSH Protocol Architecture", I-D) s
+5 349 M
+(              draft-ietf-architecture-15.txt, Oct 2003.) s
+5 327 M
+(   [SSH-TRANS]) s
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+5 283 M
+(   [SSH-USERAUTH]) s
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+5 261 M
+(              draft-ietf-userauth-18.txt, Oct 2003.) s
+5 239 M
+(   [SSH-CONNECT]) s
+5 228 M
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+5 217 M
+(              draft-ietf-connect-18.txt, Oct 2003.) s
+5 195 M
+(   [SSH-NUMBERS]) s
+5 184 M
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+5 690 M
+(              2003.) s
+5 668 M
+(   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate) s
+5 657 M
+(              Requirement Levels", BCP 14, RFC 2119, March 1997.) s
+5 635 M
+(Informative References) s
+5 613 M
+(   [RFC3066]  Alvestrand, H., "Tags for the Identification of) s
+5 602 M
+(              Languages", BCP 47, RFC 3066, January 2001.) s
+5 580 M
+(   [RFC1884]  Hinden, R. and S. Deering, "IP Version 6 Addressing) s
+5 569 M
+(              Architecture", RFC 1884, December 1995.) s
+5 547 M
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+5 536 M
+(              10646", RFC 2279, January 1998.) s
+5 514 M
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+5 503 M
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+5 492 M
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+5 481 M
+(              Press ISBN 1555580882, Feburary 1992.) s
+5 459 M
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+5 448 M
+(              Operating System Interface  \(POSIX\)-Part 1: System) s
+5 437 M
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+5 426 M
+(              Std 1003.1, July 1996.) s
+5 393 M
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+5 371 M
+(   Tatu Ylonen) s
+5 360 M
+(   SSH Communications Security Corp) s
+5 349 M
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+5 338 M
+(   HELSINKI  FIN-00100) s
+5 327 M
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+(   EMail: [email protected]) s
+5 272 M
+(   Darren J. Moffat \(editor\)) s
+5 261 M
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+5 250 M
+(   17 Network Circle) s
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+5 668 M
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+5 657 M
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+5 591 M
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+5 547 M
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+5 503 M
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+5 492 M
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+5 470 M
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+5 448 M
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+(   regard to some or all of the specification contained in this) s
+5 426 M
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+5 415 M
+(   rights.) s
+5 382 M
+(Full Copyright Statement) s
+5 360 M
+(   Copyright \(C\) The Internet Society \(2003\). All Rights Reserved.) s
+5 338 M
+(   This document and translations of it may be copied and furnished to) s
+5 327 M
+(   others, and derivative works that comment on or otherwise explain it) s
+5 316 M
+(   or assist in its implementation may be prepared, copied, published) s
+5 305 M
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+5 206 M
+(   English.) s
+5 184 M
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+(   This document and the information contained herein is provided on an) s
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+(   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING) s
+5 668 M
+(   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING) s
+5 657 M
+(   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION) s
+5 646 M
+(   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF) s
+5 635 M
+(   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.) s
+5 602 M
+(Acknowledgment) s
+5 580 M
+(   Funding for the RFC Editor function is currently provided by the) s
+5 569 M
+(   Internet Society.) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 22]) s
+_R
+S
+PStoPSsaved restore
+%%Trailer
+%%Pages: 22
+%%DocumentNeededResources: font Courier-Bold Courier 
+%%EOF
diff --git a/lib/ssh/doc/standard/draft-ietf-secsh-connect-18.txt b/lib/ssh/doc/standard/draft-ietf-secsh-connect-18.txt
new file mode 100644
index 0000000000..1cb8ad6409
--- /dev/null
+++ b/lib/ssh/doc/standard/draft-ietf-secsh-connect-18.txt
@@ -0,0 +1,1232 @@
+
+
+
+Network Working Group                                          T. Ylonen
+Internet-Draft                          SSH Communications Security Corp
+Expires: March 31, 2004                           D. Moffat, Editor, Ed.
+                                                   Sun Microsystems, Inc
+                                                                Oct 2003
+
+
+                        SSH Connection Protocol
+                    draft-ietf-secsh-connect-18.txt
+
+Status of this Memo
+
+   This document is an Internet-Draft and is in full conformance with
+   all provisions of Section 10 of RFC2026.
+
+   Internet-Drafts are working documents of the Internet Engineering
+   Task Force (IETF), its areas, and its working groups. Note that other
+   groups may also distribute working documents as Internet-Drafts.
+
+   Internet-Drafts are draft documents valid for a maximum of six months
+   and may be updated, replaced, or obsoleted by other documents at any
+   time. It is inappropriate to use Internet-Drafts as reference
+   material or to cite them other than as "work in progress."
+
+   The list of current Internet-Drafts can be accessed at http://
+   www.ietf.org/ietf/1id-abstracts.txt.
+
+   The list of Internet-Draft Shadow Directories can be accessed at
+   http://www.ietf.org/shadow.html.
+
+   This Internet-Draft will expire on March 31, 2004.
+
+Copyright Notice
+
+   Copyright (C) The Internet Society (2003). All Rights Reserved.
+
+Abstract
+
+   SSH is a protocol for secure remote login and other secure network
+   services over an insecure network.
+
+   This document describes the SSH Connection Protocol. It provides
+   interactive login sessions, remote execution of commands, forwarded
+   TCP/IP connections, and forwarded X11 connections. All of these
+   channels are multiplexed into a single encrypted tunnel.
+
+   The SSH Connection Protocol has been designed to run on top of the
+   SSH transport layer and user authentication protocols.
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 1]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+Table of Contents
+
+   1.    Contributors . . . . . . . . . . . . . . . . . . . . . . . .  3
+   2.    Introduction . . . . . . . . . . . . . . . . . . . . . . . .  3
+   3.    Conventions Used in This Document  . . . . . . . . . . . . .  3
+   4.    Global Requests  . . . . . . . . . . . . . . . . . . . . . .  3
+   5.    Channel Mechanism  . . . . . . . . . . . . . . . . . . . . .  4
+   5.1   Opening a Channel  . . . . . . . . . . . . . . . . . . . . .  4
+   5.2   Data Transfer  . . . . . . . . . . . . . . . . . . . . . . .  5
+   5.3   Closing a Channel  . . . . . . . . . . . . . . . . . . . . .  6
+   5.4   Channel-Specific Requests  . . . . . . . . . . . . . . . . .  7
+   6.    Interactive Sessions . . . . . . . . . . . . . . . . . . . .  8
+   6.1   Opening a Session  . . . . . . . . . . . . . . . . . . . . .  8
+   6.2   Requesting a Pseudo-Terminal . . . . . . . . . . . . . . . .  8
+   6.3   X11 Forwarding . . . . . . . . . . . . . . . . . . . . . . .  9
+   6.3.1 Requesting X11 Forwarding  . . . . . . . . . . . . . . . . .  9
+   6.3.2 X11 Channels . . . . . . . . . . . . . . . . . . . . . . . . 10
+   6.4   Environment Variable Passing . . . . . . . . . . . . . . . . 10
+   6.5   Starting a Shell or a Command  . . . . . . . . . . . . . . . 10
+   6.6   Session Data Transfer  . . . . . . . . . . . . . . . . . . . 11
+   6.7   Window Dimension Change Message  . . . . . . . . . . . . . . 12
+   6.8   Local Flow Control . . . . . . . . . . . . . . . . . . . . . 12
+   6.9   Signals  . . . . . . . . . . . . . . . . . . . . . . . . . . 12
+   6.10  Returning Exit Status  . . . . . . . . . . . . . . . . . . . 13
+   7.    TCP/IP Port Forwarding . . . . . . . . . . . . . . . . . . . 14
+   7.1   Requesting Port Forwarding . . . . . . . . . . . . . . . . . 14
+   7.2   TCP/IP Forwarding Channels . . . . . . . . . . . . . . . . . 15
+   8.    Encoding of Terminal Modes . . . . . . . . . . . . . . . . . 16
+   9.    Summary of Message Numbers . . . . . . . . . . . . . . . . . 18
+   10.   Security Considerations  . . . . . . . . . . . . . . . . . . 18
+   11.   iana cONSiderations  . . . . . . . . . . . . . . . . . . . . 19
+   12.   Intellectual Property  . . . . . . . . . . . . . . . . . . . 19
+         Normative References . . . . . . . . . . . . . . . . . . . . 19
+         Informative References . . . . . . . . . . . . . . . . . . . 20
+         Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 20
+         Intellectual Property and Copyright Statements . . . . . . . 21
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 2]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+1. Contributors
+
+   The major original contributors of this document were: Tatu Ylonen,
+   Tero Kivinen, Timo J. Rinne, Sami Lehtinen (all of SSH Communications
+   Security Corp), and Markku-Juhani O. Saarinen (University of
+   Jyvaskyla)
+
+   The document editor is: [email protected].  Comments on this
+   internet draft should be sent to the IETF SECSH working group,
+   details at: http://ietf.org/html.charters/secsh-charter.html
+
+2. Introduction
+
+   The SSH Connection Protocol has been designed to run on top of the
+   SSH transport layer and user authentication protocols. It provides
+   interactive login sessions, remote execution of commands, forwarded
+   TCP/IP connections, and forwarded X11 connections. The service name
+   for this protocol is "ssh-connection".
+
+   This document should be read only after reading the SSH architecture
+   document [SSH-ARCH]. This document freely uses terminology and
+   notation from the architecture document without reference or further
+   explanation.
+
+3. Conventions Used in This Document
+
+   The keywords "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT",
+   and "MAY" that appear in this document are to be interpreted as
+   described in [RFC2119].
+
+   The used data types and terminology are specified in the architecture
+   document [SSH-ARCH].
+
+   The architecture document also discusses the algorithm naming
+   conventions that MUST be used with the SSH protocols.
+
+4. Global Requests
+
+   There are several kinds of requests that affect the state of the
+   remote end "globally", independent of any channels.  An example is a
+   request to start TCP/IP forwarding for a specific port.  All such
+   requests use the following format.
+
+     byte      SSH_MSG_GLOBAL_REQUEST
+     string    request name (restricted to US-ASCII)
+     boolean   want reply
+     ... request-specific data follows
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 3]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+   Request names follow the DNS extensibility naming convention outlined
+   in [SSH-ARCH].
+
+   The recipient will respond to this message with
+   SSH_MSG_REQUEST_SUCCESS or SSH_MSG_REQUEST_FAILURE if `want reply' is
+   TRUE.
+
+     byte      SSH_MSG_REQUEST_SUCCESS
+     .....     response specific data
+
+   Usually the response specific data is non-existent.
+
+   If the recipient does not recognize or support the request, it simply
+   responds with SSH_MSG_REQUEST_FAILURE.
+
+     byte      SSH_MSG_REQUEST_FAILURE
+
+
+5. Channel Mechanism
+
+   All terminal sessions, forwarded connections, etc. are channels.
+   Either side may open a channel.  Multiple channels are multiplexed
+   into a single connection.
+
+   Channels are identified by numbers at each end.  The number referring
+   to a channel may be different on each side.  Requests to open a
+   channel contain the sender's channel number.  Any other
+   channel-related messages contain the recipient's channel number for
+   the channel.
+
+   Channels are flow-controlled.  No data may be sent to a channel until
+   a message is received to indicate that window space is available.
+
+5.1 Opening a Channel
+
+   When either side wishes to open a new channel, it allocates a local
+   number for the channel.  It then sends the following message to the
+   other side, and includes the local channel number and initial window
+   size in the message.
+
+     byte      SSH_MSG_CHANNEL_OPEN
+     string    channel type (restricted to US-ASCII)
+     uint32    sender channel
+     uint32    initial window size
+     uint32    maximum packet size
+     ... channel type specific data follows
+
+   The channel type is a name as described in the SSH architecture
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 4]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+   document, with similar extension mechanisms. `sender channel' is a
+   local identifier for the channel used by the sender of this message.
+   `initial window size' specifies how many bytes of channel data can be
+   sent to the sender of this message without adjusting the window.
+   `Maximum packet size' specifies the maximum size of an individual
+   data packet that can be sent to the sender (for example, one might
+   want to use smaller packets for interactive connections to get better
+   interactive response on slow links).
+
+   The remote side then decides whether it can open the channel, and
+   responds with either
+
+     byte      SSH_MSG_CHANNEL_OPEN_CONFIRMATION
+     uint32    recipient channel
+     uint32    sender channel
+     uint32    initial window size
+     uint32    maximum packet size
+     ... channel type specific data follows
+
+   where `recipient channel' is the channel number given in the original
+   open request, and `sender channel' is the channel number allocated by
+   the other side, or
+
+     byte      SSH_MSG_CHANNEL_OPEN_FAILURE
+     uint32    recipient channel
+     uint32    reason code
+     string    additional textual information (ISO-10646 UTF-8 [RFC2279])
+     string    language tag (as defined in [RFC3066])
+
+   If the recipient of the SSH_MSG_CHANNEL_OPEN message does not support
+   the specified channel type, it simply responds with
+   SSH_MSG_CHANNEL_OPEN_FAILURE. The client MAY show the additional
+   information to the user. If this is done, the client software should
+   take the precautions discussed in [SSH-ARCH].
+
+   The following reason codes are defined:
+
+     #define SSH_OPEN_ADMINISTRATIVELY_PROHIBITED    1
+     #define SSH_OPEN_CONNECT_FAILED                 2
+     #define SSH_OPEN_UNKNOWN_CHANNEL_TYPE           3
+     #define SSH_OPEN_RESOURCE_SHORTAGE              4
+
+
+5.2 Data Transfer
+
+   The window size specifies how many bytes the other party can send
+   before it must wait for the window to be adjusted.  Both parties use
+   the following message to adjust the window.
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 5]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+     byte      SSH_MSG_CHANNEL_WINDOW_ADJUST
+     uint32    recipient channel
+     uint32    bytes to add
+
+   After receiving this message, the recipient MAY send the given number
+   of bytes more than it was previously allowed to send; the window size
+   is incremented.
+
+   Data transfer is done with messages of the following type.
+
+     byte      SSH_MSG_CHANNEL_DATA
+     uint32    recipient channel
+     string    data
+
+   The maximum amount of data allowed is the current window size.  The
+   window size is decremented by the amount of data sent. Both parties
+   MAY ignore all extra data sent after the allowed window is empty.
+
+   Additionally, some channels can transfer several types of data.  An
+   example of this is stderr data from interactive sessions. Such data
+   can be passed with SSH_MSG_CHANNEL_EXTENDED_DATA messages, where a
+   separate integer specifies the type of the data.  The available types
+   and their interpretation depend on the type of the channel.
+
+     byte      SSH_MSG_CHANNEL_EXTENDED_DATA
+     uint32    recipient_channel
+     uint32    data_type_code
+     string    data
+
+   Data sent with these messages consumes the same window as ordinary
+   data.
+
+   Currently, only the following type is defined.
+
+   #define SSH_EXTENDED_DATA_STDERR                1
+
+
+5.3 Closing a Channel
+
+   When a party will no longer send more data to a channel, it SHOULD
+   send SSH_MSG_CHANNEL_EOF.
+
+     byte      SSH_MSG_CHANNEL_EOF
+     uint32    recipient_channel
+
+   No explicit response is sent to this message; however, the
+   application may send EOF to whatever is at the other end of the
+   channel.  Note that the channel remains open after this message, and
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 6]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+   more data may still be sent in the other direction.  This message
+   does not consume window space and can be sent even if no window space
+   is available.
+
+   When either party wishes to terminate the channel, it sends
+   SSH_MSG_CHANNEL_CLOSE.  Upon receiving this message, a party MUST
+   send back a SSH_MSG_CHANNEL_CLOSE unless it has already sent this
+   message for the channel.  The channel is considered closed for a
+   party when it has both sent and received SSH_MSG_CHANNEL_CLOSE, and
+   the party may then reuse the channel number.  A party MAY send
+   SSH_MSG_CHANNEL_CLOSE without having sent or received
+   SSH_MSG_CHANNEL_EOF.
+
+     byte      SSH_MSG_CHANNEL_CLOSE
+     uint32    recipient_channel
+
+   This message does not consume window space and can be sent even if no
+   window space is available.
+
+   It is recommended that any data sent before this message is delivered
+   to the actual destination, if possible.
+
+5.4 Channel-Specific Requests
+
+   Many channel types have extensions that are specific to that
+   particular channel type.  An example is requesting a pty (pseudo
+   terminal) for an interactive session.
+
+   All channel-specific requests use the following format.
+
+     byte      SSH_MSG_CHANNEL_REQUEST
+     uint32    recipient channel
+     string    request type (restricted to US-ASCII)
+     boolean   want reply
+     ... type-specific data
+
+   If want reply is FALSE, no response will be sent to the request.
+   Otherwise, the recipient responds with either SSH_MSG_CHANNEL_SUCCESS
+   or SSH_MSG_CHANNEL_FAILURE, or request-specific continuation
+   messages. If the request is not recognized or is not supported for
+   the channel, SSH_MSG_CHANNEL_FAILURE is returned.
+
+   This message does not consume window space and can be sent even if no
+   window space is available. Request types are local to each channel
+   type.
+
+   The client is allowed to send further messages without waiting for
+   the response to the request.
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 7]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+   request type names follow the DNS extensibility naming convention
+   outlined in [SSH-ARCH]
+
+     byte      SSH_MSG_CHANNEL_SUCCESS
+     uint32    recipient_channel
+
+
+     byte      SSH_MSG_CHANNEL_FAILURE
+     uint32    recipient_channel
+
+   These messages do not consume window space and can be sent even if no
+   window space is available.
+
+6. Interactive Sessions
+
+   A session is a remote execution of a program.  The program may be a
+   shell, an application, a system command, or some built-in subsystem.
+   It may or may not have a tty, and may or may not involve X11
+   forwarding. Multiple sessions can be active simultaneously.
+
+6.1 Opening a Session
+
+   A session is started by sending the following message.
+
+     byte      SSH_MSG_CHANNEL_OPEN
+     string    "session"
+     uint32    sender channel
+     uint32    initial window size
+     uint32    maximum packet size
+
+   Client implementations SHOULD reject any session channel open
+   requests to make it more difficult for a corrupt server to attack the
+   client.
+
+6.2 Requesting a Pseudo-Terminal
+
+   A pseudo-terminal can be allocated for the session by sending the
+   following message.
+
+     byte      SSH_MSG_CHANNEL_REQUEST
+     uint32    recipient_channel
+     string    "pty-req"
+     boolean   want_reply
+     string    TERM environment variable value (e.g., vt100)
+     uint32    terminal width, characters (e.g., 80)
+     uint32    terminal height, rows (e.g., 24)
+     uint32    terminal width, pixels (e.g., 640)
+     uint32    terminal height, pixels (e.g., 480)
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 8]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+     string    encoded terminal modes
+
+   The encoding of terminal modes is described in Section Encoding of
+   Terminal Modes (Section 8). Zero dimension parameters MUST be
+   ignored. The character/row dimensions override the pixel dimensions
+   (when nonzero). Pixel dimensions refer to the drawable area of the
+   window.
+
+   The dimension parameters are only informational.
+
+   The client SHOULD ignore pty requests.
+
+6.3 X11 Forwarding
+
+6.3.1 Requesting X11 Forwarding
+
+   X11 forwarding may be requested for a session by sending
+
+     byte      SSH_MSG_CHANNEL_REQUEST
+     uint32    recipient channel
+     string    "x11-req"
+     boolean   want reply
+     boolean   single connection
+     string    x11 authentication protocol
+     string    x11 authentication cookie
+     uint32    x11 screen number
+
+   It is recommended that the authentication cookie that is sent be a
+   fake, random cookie, and that the cookie is checked and replaced by
+   the real cookie when a connection request is received.
+
+   X11 connection forwarding should stop when the session channel is
+   closed; however, already opened forwardings should not be
+   automatically closed when the session channel is closed.
+
+   If `single connection' is TRUE, only a single connection should be
+   forwarded.  No more connections will be forwarded after the first, or
+   after the session channel has been closed.
+
+   The "x11 authentication protocol" is the name of the X11
+   authentication method used, e.g. "MIT-MAGIC-COOKIE-1".
+
+   The x11 authentication cookie MUST be hexadecimal encoded.
+
+   X Protocol is documented in [SCHEIFLER].
+
+
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 9]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+6.3.2 X11 Channels
+
+   X11 channels are opened with a channel open request.  The resulting
+   channels are independent of the session, and closing the session
+   channel does not close the forwarded X11 channels.
+
+     byte      SSH_MSG_CHANNEL_OPEN
+     string    "x11"
+     uint32    sender channel
+     uint32    initial window size
+     uint32    maximum packet size
+     string    originator address (e.g. "192.168.7.38")
+     uint32    originator port
+
+   The recipient should respond with SSH_MSG_CHANNEL_OPEN_CONFIRMATION
+   or SSH_MSG_CHANNEL_OPEN_FAILURE.
+
+   Implementations MUST reject any X11 channel open requests if they
+   have not requested X11 forwarding.
+
+6.4 Environment Variable Passing
+
+   Environment variables may be passed to the shell/command to be
+   started later. Uncontrolled setting of environment variables in a
+   privileged process can be a security hazard.  It is recommended that
+   implementations either maintain a list of allowable variable names or
+   only set environment variables after the server process has dropped
+   sufficient privileges.
+
+     byte      SSH_MSG_CHANNEL_REQUEST
+     uint32    recipient channel
+     string    "env"
+     boolean   want reply
+     string    variable name
+     string    variable value
+
+
+6.5 Starting a Shell or a Command
+
+   Once the session has been set up, a program is started at the remote
+   end. The program can be a shell, an application program or a
+   subsystem with a host-independent name.  Only one of these requests
+   can succeed per channel.
+
+     byte      SSH_MSG_CHANNEL_REQUEST
+     uint32    recipient channel
+     string    "shell"
+     boolean   want reply
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 10]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+   This message will request the user's default shell (typically defined
+   in /etc/passwd in UNIX systems) to be started at the other end.
+
+     byte      SSH_MSG_CHANNEL_REQUEST
+     uint32    recipient channel
+     string    "exec"
+     boolean   want reply
+     string    command
+
+   This message will request the server to start the execution of the
+   given command. The command string may contain a path. Normal
+   precautions MUST be taken to prevent the execution of unauthorized
+   commands.
+
+     byte      SSH_MSG_CHANNEL_REQUEST
+     uint32    recipient channel
+     string    "subsystem"
+     boolean   want reply
+     string    subsystem name
+
+   This last form executes a predefined subsystem.  It is expected that
+   these will include a general file transfer mechanism, and possibly
+   other features.  Implementations may also allow configuring more such
+   mechanisms. As the user's shell is usually used to execute the
+   subsystem, it is advisable for the subsystem protocol to have a
+   "magic cookie" at the beginning of the protocol transaction to
+   distinguish it from arbitrary output generated by shell
+   initialization scripts etc. This spurious output from the shell may
+   be filtered out either at the server or at the client.
+
+   The server SHOULD not halt the execution of the protocol stack when
+   starting a shell or a program. All input and output from these SHOULD
+   be redirected to the channel or to the encrypted tunnel.
+
+   It is RECOMMENDED to request and check the reply for these messages.
+   The client SHOULD ignore these messages.
+
+   Subsystem names follow the DNS extensibility naming convention
+   outlined in [SSH-ARCH].
+
+6.6 Session Data Transfer
+
+   Data transfer for a session is done using SSH_MSG_CHANNEL_DATA and
+   SSH_MSG_CHANNEL_EXTENDED_DATA packets and the window mechanism.  The
+   extended data type SSH_EXTENDED_DATA_STDERR has been defined for
+   stderr data.
+
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 11]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+6.7 Window Dimension Change Message
+
+   When the window (terminal) size changes on the client side, it MAY
+   send a message to the other side to inform it of the new dimensions.
+
+     byte      SSH_MSG_CHANNEL_REQUEST
+     uint32    recipient_channel
+     string    "window-change"
+     boolean   FALSE
+     uint32    terminal width, columns
+     uint32    terminal height, rows
+     uint32    terminal width, pixels
+     uint32    terminal height, pixels
+
+    No response SHOULD be sent to this message.
+
+6.8 Local Flow Control
+
+   On many systems, it is possible to determine if a pseudo-terminal is
+   using control-S/control-Q flow control.  When flow control is
+   allowed, it is often desirable to do the flow control at the client
+   end to speed up responses to user requests.  This is facilitated by
+   the following notification.  Initially, the server is responsible for
+   flow control. (Here, again, client means the side originating the
+   session, and server means the other side.)
+
+   The message below is used by the server to inform the client when it
+   can or cannot perform flow control (control-S/control-Q processing).
+   If `client can do' is TRUE, the client is allowed to do flow control
+   using control-S and control-Q.  The client MAY ignore this message.
+
+     byte      SSH_MSG_CHANNEL_REQUEST
+     uint32    recipient channel
+     string    "xon-xoff"
+     boolean   FALSE
+     boolean   client can do
+
+   No response is sent to this message.
+
+6.9 Signals
+
+   A signal can be delivered to the remote process/service using the
+   following message.  Some systems may not implement signals, in which
+   case they SHOULD ignore this message.
+
+     byte      SSH_MSG_CHANNEL_REQUEST
+     uint32    recipient channel
+     string    "signal"
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 12]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+     boolean   FALSE
+     string    signal name without the "SIG" prefix.
+
+   Signal names will be encoded as discussed in the "exit-signal"
+   SSH_MSG_CHANNEL_REQUEST.
+
+6.10 Returning Exit Status
+
+   When the command running at the other end terminates, the following
+   message can be sent to return the exit status of the command.
+   Returning the status is RECOMMENDED.  No acknowledgment is sent for
+   this message.  The channel needs to be closed with
+   SSH_MSG_CHANNEL_CLOSE after this message.
+
+   The client MAY ignore these messages.
+
+     byte      SSH_MSG_CHANNEL_REQUEST
+     uint32    recipient_channel
+     string    "exit-status"
+     boolean   FALSE
+     uint32    exit_status
+
+   The remote command may also terminate violently due to a signal.
+   Such a condition can be indicated by the following message. A zero
+   exit_status usually means that the command terminated successfully.
+
+     byte      SSH_MSG_CHANNEL_REQUEST
+     uint32    recipient channel
+     string    "exit-signal"
+     boolean   FALSE
+     string    signal name without the "SIG" prefix.
+     boolean   core dumped
+     string    error message (ISO-10646 UTF-8)
+     string    language tag (as defined in [RFC3066])
+
+   The signal name is one of the following (these are from [POSIX])
+
+     ABRT
+     ALRM
+     FPE
+     HUP
+     ILL
+     INT
+     KILL
+     PIPE
+     QUIT
+     SEGV
+     TERM
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 13]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+     USR1
+     USR2
+
+   Additional signal names MAY be sent in the format "sig-name@xyz",
+   where `sig-name' and `xyz' may be anything a particular implementor
+   wants (except the `@' sign). However, it is suggested that if a
+   `configure' script is used, the non-standard signal names it finds be
+   encoded as "[email protected]", where `SIG' is the signal name
+   without the "SIG" prefix, and `xyz' be the host type, as determined
+   by `config.guess'.
+
+   The `error message' contains an additional explanation of the error
+   message. The message may consist of multiple lines. The client
+   software MAY display this message to the user. If this is done, the
+   client software should take the precautions discussed in [SSH-ARCH].
+
+7. TCP/IP Port Forwarding
+
+7.1 Requesting Port Forwarding
+
+   A party need not explicitly request forwardings from its own end to
+   the other direction.  However, if it wishes that connections to a
+   port on the other side be forwarded to the local side, it must
+   explicitly request this.
+
+
+     byte      SSH_MSG_GLOBAL_REQUEST
+     string    "tcpip-forward"
+     boolean   want reply
+     string    address to bind (e.g. "0.0.0.0")
+     uint32    port number to bind
+
+   `Address to bind' and `port number to bind' specify the IP address
+   and port to which the socket to be listened is bound.  The address
+   should be "0.0.0.0" if connections are allowed from anywhere. (Note
+   that the client can still filter connections based on information
+   passed in the open request.)
+
+   Implementations should only allow forwarding privileged ports if the
+   user has been authenticated as a privileged user.
+
+   Client implementations SHOULD reject these messages; they are
+   normally only sent by the client.
+
+
+   If a client passes 0 as port number to bind and has want reply TRUE
+   then the server allocates the next available unprivileged port number
+   and replies with the following message, otherwise there is no
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 14]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+   response specific data.
+
+
+     byte     SSH_MSG_GLOBAL_REQUEST_SUCCESS
+     uint32   port that was bound on the server
+
+   A port forwarding can be cancelled with the following message.  Note
+   that channel open requests may be received until a reply to this
+   message is received.
+
+     byte      SSH_MSG_GLOBAL_REQUEST
+     string    "cancel-tcpip-forward"
+     boolean   want reply
+     string    address_to_bind (e.g. "127.0.0.1")
+     uint32    port number to bind
+
+   Client implementations SHOULD reject these messages; they are
+   normally only sent by the client.
+
+7.2 TCP/IP Forwarding Channels
+
+   When a connection comes to a port for which remote forwarding has
+   been requested, a channel is opened to forward the port to the other
+   side.
+
+     byte      SSH_MSG_CHANNEL_OPEN
+     string    "forwarded-tcpip"
+     uint32    sender channel
+     uint32    initial window size
+     uint32    maximum packet size
+     string    address that was connected
+     uint32    port that was connected
+     string    originator IP address
+     uint32    originator port
+
+   Implementations MUST reject these messages unless they have
+   previously requested a remote TCP/IP port forwarding with the given
+   port number.
+
+   When a connection comes to a locally forwarded TCP/IP port, the
+   following packet is sent to the other side.  Note that these messages
+   MAY be sent also for ports for which no forwarding has been
+   explicitly requested.  The receiving side must decide whether to
+   allow the forwarding.
+
+     byte      SSH_MSG_CHANNEL_OPEN
+     string    "direct-tcpip"
+     uint32    sender channel
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 15]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+     uint32    initial window size
+     uint32    maximum packet size
+     string    host to connect
+     uint32    port to connect
+     string    originator IP address
+     uint32    originator port
+
+   `Host to connect' and `port to connect' specify the TCP/IP host and
+   port where the recipient should connect the channel. `Host to
+   connect' may be either a domain name or a numeric IP address.
+
+   `Originator IP address' is the numeric IP address of the machine
+   where the connection request comes from, and `originator port' is the
+   port on the originator host from where the connection came from.
+
+   Forwarded TCP/IP channels are independent of any sessions, and
+   closing a session channel does not in any way imply that forwarded
+   connections should be closed.
+
+   Client implementations SHOULD reject direct TCP/IP open requests for
+   security reasons.
+
+8. Encoding of Terminal Modes
+
+   Terminal modes (as passed in a pty request) are encoded into a byte
+   stream.  It is intended that the coding be portable across different
+   environments.
+
+   The tty mode description is a stream of bytes.  The stream consists
+   of opcode-argument pairs.  It is terminated by opcode TTY_OP_END (0).
+   Opcodes 1 to 159 have a single uint32 argument. Opcodes 160 to 255
+   are not yet defined, and cause parsing to stop (they should only be
+   used after any other data).
+
+   The client SHOULD put in the stream any modes it knows about, and the
+   server MAY ignore any modes it does not know about.  This allows some
+   degree of machine-independence, at least between systems that use a
+   POSIX-like tty interface.  The protocol can support other systems as
+   well, but the client may need to fill reasonable values for a number
+   of parameters so the server pty gets set to a reasonable mode (the
+   server leaves all unspecified mode bits in their default values, and
+   only some combinations make sense).
+
+   The following opcodes have been defined.  The naming of opcodes
+   mostly follows the POSIX terminal mode flags.
+
+   0   TTY_OP_END     Indicates end of options.
+   1   VINTR          Interrupt character; 255 if none.  Similarly for the
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 16]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+                      other characters. Not all of these characters are
+                      supported on all systems.
+   2   VQUIT          The quit character (sends SIGQUIT signal on POSIX
+                      systems).
+   3   VERASE         Erase the character to left of the cursor.
+   4   VKILL          Kill the current input line.
+   5   VEOF           End-of-file character (sends EOF from the terminal).
+   6   VEOL           End-of-line character in addition to carriage return
+                      and/or linefeed.
+   7   VEOL2          Additional end-of-line character.
+   8   VSTART         Continues paused output (normally control-Q).
+   9   VSTOP          Pauses output (normally control-S).
+   10  VSUSP          Suspends the current program.
+   11  VDSUSP         Another suspend character.
+   12  VREPRINT       Reprints the current input line.
+   13  VWERASE        Erases a word left of cursor.
+   14  VLNEXT         Enter the next character typed literally, even if it
+                      is a special character
+   15  VFLUSH         Character to flush output.
+   16  VSWTCH         Switch to a different shell layer.
+   17  VSTATUS        Prints system status line (load, command, pid etc).
+   18  VDISCARD       Toggles the flushing of terminal output.
+   30  IGNPAR         The ignore parity flag.  The parameter SHOULD be 0 if
+                      this flag is FALSE set, and 1 if it is TRUE.
+   31  PARMRK         Mark parity and framing errors.
+   32  INPCK          Enable checking of parity errors.
+   33  ISTRIP         Strip 8th bit off characters.
+   34  INLCR          Map NL into CR on input.
+   35  IGNCR          Ignore CR on input.
+   36  ICRNL          Map CR to NL on input.
+   37  IUCLC          Translate uppercase characters to lowercase.
+   38  IXON           Enable output flow control.
+   39  IXANY          Any char will restart after stop.
+   40  IXOFF          Enable input flow control.
+   41  IMAXBEL        Ring bell on input queue full.
+   50  ISIG           Enable signals INTR, QUIT, [D]SUSP.
+   51  ICANON         Canonicalize input lines.
+   52  XCASE          Enable input and output of uppercase characters by
+                      preceding their lowercase equivalents with `\'.
+   53  ECHO           Enable echoing.
+   54  ECHOE          Visually erase chars.
+   55  ECHOK          Kill character discards current line.
+   56  ECHONL         Echo NL even if ECHO is off.
+   57  NOFLSH         Don't flush after interrupt.
+   58  TOSTOP         Stop background jobs from output.
+   59  IEXTEN         Enable extensions.
+   60  ECHOCTL        Echo control characters as ^(Char).
+   61  ECHOKE         Visual erase for line kill.
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 17]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+   62  PENDIN         Retype pending input.
+   70  OPOST          Enable output processing.
+   71  OLCUC          Convert lowercase to uppercase.
+   72  ONLCR          Map NL to CR-NL.
+   73  OCRNL          Translate carriage return to newline (output).
+   74  ONOCR          Translate newline to carriage return-newline
+                      (output).
+   75  ONLRET         Newline performs a carriage return (output).
+   90  CS7            7 bit mode.
+   91  CS8            8 bit mode.
+   92  PARENB         Parity enable.
+   93  PARODD         Odd parity, else even.
+
+   128 TTY_OP_ISPEED  Specifies the input baud rate in bits per second.
+   129 TTY_OP_OSPEED  Specifies the output baud rate in bits per second.
+
+
+9. Summary of Message Numbers
+
+     #define SSH_MSG_GLOBAL_REQUEST                  80
+     #define SSH_MSG_REQUEST_SUCCESS                 81
+     #define SSH_MSG_REQUEST_FAILURE                 82
+     #define SSH_MSG_CHANNEL_OPEN                    90
+     #define SSH_MSG_CHANNEL_OPEN_CONFIRMATION       91
+     #define SSH_MSG_CHANNEL_OPEN_FAILURE            92
+     #define SSH_MSG_CHANNEL_WINDOW_ADJUST           93
+     #define SSH_MSG_CHANNEL_DATA                    94
+     #define SSH_MSG_CHANNEL_EXTENDED_DATA           95
+     #define SSH_MSG_CHANNEL_EOF                     96
+     #define SSH_MSG_CHANNEL_CLOSE                   97
+     #define SSH_MSG_CHANNEL_REQUEST                 98
+     #define SSH_MSG_CHANNEL_SUCCESS                 99
+     #define SSH_MSG_CHANNEL_FAILURE                 100
+
+
+10. Security Considerations
+
+   This protocol is assumed to run on top of a secure, authenticated
+   transport.  User authentication and protection against network-level
+   attacks are assumed to be provided by the underlying protocols.
+
+   It is RECOMMENDED that implementations disable all the potentially
+   dangerous features (e.g. agent forwarding, X11 forwarding, and TCP/IP
+   forwarding) if the host key has changed.
+
+   Full security considerations for this protocol are provided in
+   Section 8 of [SSH-ARCH]
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 18]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+11. iana cONSiderations
+
+   This document is part of a set, the IANA considerations for the SSH
+   protocol as defined in [SSH-ARCH], [SSH-TRANS], [SSH-USERAUTH],
+   [SSH-CONNECT] are detailed in [SSH-NUMBERS].
+
+12. Intellectual Property
+
+   The IETF takes no position regarding the validity or scope of any
+   intellectual property or other rights that might be claimed to
+   pertain to the implementation or use of the technology described in
+   this document or the extent to which any license under such rights
+   might or might not be available; neither does it represent that it
+   has made any effort to identify any such rights. Information on the
+   IETF's procedures with respect to rights in standards-track and
+   standards-related documentation can be found in BCP-11. Copies of
+   claims of rights made available for publication and any assurances of
+   licenses to be made available, or the result of an attempt made to
+   obtain a general license or permission for the use of such
+   proprietary rights by implementers or users of this specification can
+   be obtained from the IETF Secretariat.
+
+   The IETF has been notified of intellectual property rights claimed in
+   regard to some or all of the specification contained in this
+   document. For more information consult the online list of claimed
+   rights.
+
+Normative References
+
+   [SSH-ARCH]
+              Ylonen, T., "SSH Protocol Architecture", I-D
+              draft-ietf-architecture-15.txt, Oct 2003.
+
+   [SSH-TRANS]
+              Ylonen, T., "SSH Transport Layer Protocol", I-D
+              draft-ietf-transport-17.txt, Oct 2003.
+
+   [SSH-USERAUTH]
+              Ylonen, T., "SSH Authentication Protocol", I-D
+              draft-ietf-userauth-18.txt, Oct 2003.
+
+   [SSH-CONNECT]
+              Ylonen, T., "SSH Connection Protocol", I-D
+              draft-ietf-connect-18.txt, Oct 2003.
+
+   [SSH-NUMBERS]
+              Lehtinen, S. and D. Moffat, "SSH Protocol Assigned
+              Numbers", I-D draft-ietf-secsh-assignednumbers-05.txt, Oct
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 19]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+              2003.
+
+   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
+              Requirement Levels", BCP 14, RFC 2119, March 1997.
+
+Informative References
+
+   [RFC3066]  Alvestrand, H., "Tags for the Identification of
+              Languages", BCP 47, RFC 3066, January 2001.
+
+   [RFC1884]  Hinden, R. and S. Deering, "IP Version 6 Addressing
+              Architecture", RFC 1884, December 1995.
+
+   [RFC2279]  Yergeau, F., "UTF-8, a transformation format of ISO
+              10646", RFC 2279, January 1998.
+
+   [SCHEIFLER]
+              Scheifler, R., "X Window System : The Complete Reference
+              to Xlib, X Protocol, Icccm, Xlfd, 3rd edition.", Digital
+              Press ISBN 1555580882, Feburary 1992.
+
+   [POSIX]    ISO/IEC, 9945-1., "Information technology -- Portable
+              Operating System Interface  (POSIX)-Part 1: System
+              Application Program Interface (API) C Language", ANSI/IEE
+              Std 1003.1, July 1996.
+
+
+Authors' Addresses
+
+   Tatu Ylonen
+   SSH Communications Security Corp
+   Fredrikinkatu 42
+   HELSINKI  FIN-00100
+   Finland
+
+   EMail: [email protected]
+
+
+   Darren J. Moffat (editor)
+   Sun Microsystems, Inc
+   17 Network Circle
+   Menlo Park  CA 94025
+   USA
+
+   EMail: [email protected]
+
+
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 20]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+Intellectual Property Statement
+
+   The IETF takes no position regarding the validity or scope of any
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+   pertain to the implementation or use of the technology described in
+   this document or the extent to which any license under such rights
+   might or might not be available; neither does it represent that it
+   has made any effort to identify any such rights. Information on the
+   IETF's procedures with respect to rights in standards-track and
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+
+Full Copyright Statement
+
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+
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+
+   The limited permissions granted above are perpetual and will not be
+   revoked by the Internet Society or its successors or assignees.
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 21]
+
+Internet-Draft          SSH Connection Protocol                 Oct 2003
+
+
+   This document and the information contained herein is provided on an
+   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
+   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
+   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
+   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
+   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+
+
+Acknowledgment
+
+   Funding for the RFC Editor function is currently provided by the
+   Internet Society.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 22]
\ No newline at end of file
diff --git a/lib/ssh/doc/standard/draft-ietf-secsh-filexfer-02.2.ps b/lib/ssh/doc/standard/draft-ietf-secsh-filexfer-02.2.ps
new file mode 100644
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+(   http://www.ietf.org/shadow.html.) s
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+(   This Internet-Draft will expire on April 1, 2002.) s
+5 349 M
+(Copyright Notice) s
+5 327 M
+(   Copyright \(C\) The Internet Society \(2001\).  All Rights Reserved.) s
+5 305 M
+(Abstract) s
+5 283 M
+(   The SSH File Transfer Protocol provides secure file transfer) s
+5 272 M
+(   functionality over any reliable data stream.  It is the standard file) s
+5 261 M
+(   transfer protocol for use with the SSH2 protocol.  This document) s
+5 250 M
+(   describes the file transfer protocol and its interface to the SSH2) s
+5 239 M
+(   protocol suite.) s
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+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
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+(Table of Contents) s
+5 668 M
+(   1.   Introduction . . . . . . . . . . . . . . . . . . . . . . . .   3) s
+5 657 M
+(   2.   Use with the SSH Connection Protocol . . . . . . . . . . . .   4) s
+5 646 M
+(   3.   General Packet Format  . . . . . . . . . . . . . . . . . . .   5) s
+5 635 M
+(   4.   Protocol Initialization  . . . . . . . . . . . . . . . . . .   7) s
+5 624 M
+(   5.   File Attributes  . . . . . . . . . . . . . . . . . . . . . .   8) s
+5 613 M
+(   6.   Requests From the Client to the Server . . . . . . . . . . .  10) s
+5 602 M
+(   6.1  Request Synchronization and Reordering . . . . . . . . . . .  10) s
+5 591 M
+(   6.2  File Names . . . . . . . . . . . . . . . . . . . . . . . . .  11) s
+5 580 M
+(   6.3  Opening, Creating, and Closing Files . . . . . . . . . . . .  11) s
+5 569 M
+(   6.4  Reading and Writing  . . . . . . . . . . . . . . . . . . . .  13) s
+5 558 M
+(   6.5  Removing and Renaming Files  . . . . . . . . . . . . . . . .  14) s
+5 547 M
+(   6.6  Creating and Deleting Directories  . . . . . . . . . . . . .  15) s
+5 536 M
+(   6.7  Scanning Directories . . . . . . . . . . . . . . . . . . . .  15) s
+5 525 M
+(   6.8  Retrieving File Attributes . . . . . . . . . . . . . . . . .  16) s
+5 514 M
+(   6.9  Setting File Attributes  . . . . . . . . . . . . . . . . . .  17) s
+5 503 M
+(   6.10 Dealing with Symbolic links  . . . . . . . . . . . . . . . .  18) s
+5 492 M
+(   6.11 Canonicalizing the Server-Side Path Name . . . . . . . . . .  18) s
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+(   7.   Responses from the Server to the Client  . . . . . . . . . .  20) s
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+(   8.   Vendor-Specific Extensions . . . . . . . . . . . . . . . . .  24) s
+5 459 M
+(   9.   Security Considerations  . . . . . . . . . . . . . . . . . .  25) s
+5 448 M
+(   10.  Changes from previous protocol versions  . . . . . . . . . .  26) s
+5 437 M
+(   10.1 Changes between versions 3 and 2 . . . . . . . . . . . . . .  26) s
+5 426 M
+(   10.2 Changes between versions 2 and 1 . . . . . . . . . . . . . .  26) s
+5 415 M
+(   10.3 Changes between versions 1 and 0 . . . . . . . . . . . . . .  26) s
+5 404 M
+(   11.  Trademark Issues . . . . . . . . . . . . . . . . . . . . . .  27) s
+5 393 M
+(        References . . . . . . . . . . . . . . . . . . . . . . . . .  28) s
+5 382 M
+(        Authors' Addresses . . . . . . . . . . . . . . . . . . . . .  28) s
+5 371 M
+(        Full Copyright Statement . . . . . . . . . . . . . . . . . .  29) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                 [Page 2]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (2,3) 2
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 3 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(1. Introduction) s
+5 668 M
+(   This protocol provides secure file transfer \(and more generally file) s
+5 657 M
+(   system access\) functionality over a reliable data stream, such as a) s
+5 646 M
+(   channel in the SSH2 protocol [3].) s
+5 624 M
+(   This protocol is designed so that it could be used to implement a) s
+5 613 M
+(   secure remote file system service, as well as a secure file transfer) s
+5 602 M
+(   service.) s
+5 580 M
+(   This protocol assumes that it runs over a secure channel, and that) s
+5 569 M
+(   the server has already authenticated the user at the client end, and) s
+5 558 M
+(   that the identity of the client user is externally available to the) s
+5 547 M
+(   server implementation.) s
+5 525 M
+(   In general, this protocol follows a simple request-response model.) s
+5 514 M
+(   Each request and response contains a sequence number and multiple) s
+5 503 M
+(   requests may be pending simultaneously.  There are a relatively large) s
+5 492 M
+(   number of different request messages, but a small number of possible) s
+5 481 M
+(   response messages.  Each request has one or more response messages) s
+5 470 M
+(   that may be returned in result \(e.g., a read either returns data or) s
+5 459 M
+(   reports error status\).) s
+5 437 M
+(   The packet format descriptions in this specification follow the) s
+5 426 M
+(   notation presented in the secsh architecture draft.[3].) s
+5 404 M
+(   Even though this protocol is described in the context of the SSH2) s
+5 393 M
+(   protocol, this protocol is general and independent of the rest of the) s
+5 382 M
+(   SSH2 protocol suite.  It could be used in a number of different) s
+5 371 M
+(   applications, such as secure file transfer over TLS RFC 2246 [1] and) s
+5 360 M
+(   transfer of management information in VPN applications.) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                 [Page 3]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 4 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(2. Use with the SSH Connection Protocol) s
+5 668 M
+(   When used with the SSH2 Protocol suite, this protocol is intended to) s
+5 657 M
+(   be used from the SSH Connection Protocol [5] as a subsystem, as) s
+5 646 M
+(   described in section ``Starting a Shell or a Command''.  The) s
+5 635 M
+(   subsystem name used with this protocol is "sftp".) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                 [Page 4]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (4,5) 3
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 5 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(3. General Packet Format) s
+5 668 M
+(    All packets transmitted over the secure connection are of the) s
+5 657 M
+(   following format:) s
+5 635 M
+(        uint32             length) s
+5 624 M
+(        byte               type) s
+5 613 M
+(        byte[length - 1]   data payload) s
+5 591 M
+(   That is, they are just data preceded by 32-bit length and 8-bit type) s
+5 580 M
+(   fields.  The `length' is the length of the data area, and does not) s
+5 569 M
+(   include the `length' field itself.  The format and interpretation of) s
+5 558 M
+(   the data area depends on the packet type.) s
+5 536 M
+(   All packet descriptions below only specify the packet type and the) s
+5 525 M
+(   data that goes into the data field.  Thus, they should be prefixed by) s
+5 514 M
+(   the `length' and `type' fields.) s
+5 492 M
+(   The maximum size of a packet is in practice determined by the client) s
+5 481 M
+(   \(the maximum size of read or write requests that it sends, plus a few) s
+5 470 M
+(   bytes of packet overhead\).  All servers SHOULD support packets of at) s
+5 459 M
+(   least 34000 bytes \(where the packet size refers to the full length,) s
+5 448 M
+(   including the header above\).  This should allow for reads and writes) s
+5 437 M
+(   of at most 32768 bytes.) s
+5 415 M
+(   There is no limit on the number of outstanding \(non-acknowledged\)) s
+5 404 M
+(   requests that the client may send to the server.  In practice this is) s
+5 393 M
+(   limited by the buffering available on the data stream and the queuing) s
+5 382 M
+(   performed by the server.  If the server's queues are full, it should) s
+5 371 M
+(   not read any more data from the stream, and flow control will prevent) s
+5 360 M
+(   the client from sending more requests.  Note, however, that while) s
+5 349 M
+(   there is no restriction on the protocol level, the client's API may) s
+5 338 M
+(   provide a limit in order to prevent infinite queuing of outgoing) s
+5 327 M
+(   requests at the client.) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                 [Page 5]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 6 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(   The following values are defined for packet types.) s
+5 668 M
+(        #define SSH_FXP_INIT                1) s
+5 657 M
+(        #define SSH_FXP_VERSION             2) s
+5 646 M
+(        #define SSH_FXP_OPEN                3) s
+5 635 M
+(        #define SSH_FXP_CLOSE               4) s
+5 624 M
+(        #define SSH_FXP_READ                5) s
+5 613 M
+(        #define SSH_FXP_WRITE               6) s
+5 602 M
+(        #define SSH_FXP_LSTAT               7) s
+5 591 M
+(        #define SSH_FXP_FSTAT               8) s
+5 580 M
+(        #define SSH_FXP_SETSTAT             9) s
+5 569 M
+(        #define SSH_FXP_FSETSTAT           10) s
+5 558 M
+(        #define SSH_FXP_OPENDIR            11) s
+5 547 M
+(        #define SSH_FXP_READDIR            12) s
+5 536 M
+(        #define SSH_FXP_REMOVE             13) s
+5 525 M
+(        #define SSH_FXP_MKDIR              14) s
+5 514 M
+(        #define SSH_FXP_RMDIR              15) s
+5 503 M
+(        #define SSH_FXP_REALPATH           16) s
+5 492 M
+(        #define SSH_FXP_STAT               17) s
+5 481 M
+(        #define SSH_FXP_RENAME             18) s
+5 470 M
+(        #define SSH_FXP_READLINK           19) s
+5 459 M
+(        #define SSH_FXP_SYMLINK            20) s
+5 448 M
+(        #define SSH_FXP_STATUS            101) s
+5 437 M
+(        #define SSH_FXP_HANDLE            102) s
+5 426 M
+(        #define SSH_FXP_DATA              103) s
+5 415 M
+(        #define SSH_FXP_NAME              104) s
+5 404 M
+(        #define SSH_FXP_ATTRS             105) s
+5 393 M
+(        #define SSH_FXP_EXTENDED          200) s
+5 382 M
+(        #define SSH_FXP_EXTENDED_REPLY    201) s
+5 360 M
+(   Additional packet types should only be defined if the protocol) s
+5 349 M
+(   version number \(see Section ``Protocol Initialization''\) is) s
+5 338 M
+(   incremented, and their use MUST be negotiated using the version) s
+5 327 M
+(   number.  However, the SSH_FXP_EXTENDED and SSH_FXP_EXTENDED_REPLY) s
+5 316 M
+(   packets can be used to implement vendor-specific extensions.  See) s
+5 305 M
+(   Section ``Vendor-Specific-Extensions'' for more details.) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                 [Page 6]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (6,7) 4
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 7 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(4. Protocol Initialization) s
+5 668 M
+(   When the file transfer protocol starts, it first sends a SSH_FXP_INIT) s
+5 657 M
+(   \(including its version number\) packet to the server.  The server) s
+5 646 M
+(   responds with a SSH_FXP_VERSION packet, supplying the lowest of its) s
+5 635 M
+(   own and the client's version number.  Both parties should from then) s
+5 624 M
+(   on adhere to particular version of the protocol.) s
+5 602 M
+(   The SSH_FXP_INIT packet \(from client to server\) has the following) s
+5 591 M
+(   data:) s
+5 569 M
+(        uint32 version) s
+5 558 M
+(        <extension data>) s
+5 536 M
+(    The SSH_FXP_VERSION packet \(from server to client\) has the following) s
+5 525 M
+(   data:) s
+5 503 M
+(        uint32 version) s
+5 492 M
+(        <extension data>) s
+5 470 M
+(   The version number of the protocol specified in this document is 3.) s
+5 459 M
+(   The version number should be incremented for each incompatible) s
+5 448 M
+(   revision of this protocol.) s
+5 426 M
+(    The extension data in the above packets may be empty, or may be a) s
+5 415 M
+(   sequence of) s
+5 393 M
+(        string extension_name) s
+5 382 M
+(        string extension_data) s
+5 360 M
+(   pairs \(both strings MUST always be present if one is, but the) s
+5 349 M
+(   `extension_data' string may be of zero length\).  If present, these) s
+5 338 M
+(   strings indicate extensions to the baseline protocol.  The) s
+5 327 M
+(   `extension_name' field\(s\) identify the name of the extension.  The) s
+5 316 M
+(   name should be of the form "name@domain", where the domain is the DNS) s
+5 305 M
+(   domain name of the organization defining the extension.  Additional) s
+5 294 M
+(   names that are not of this format may be defined later by the IETF.) s
+5 283 M
+(   Implementations MUST silently ignore any extensions whose name they) s
+5 272 M
+(   do not recognize.) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                 [Page 7]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 8 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(5. File Attributes) s
+5 668 M
+(   A new compound data type is defined for encoding file attributes.  It) s
+5 657 M
+(   is basically just a combination of elementary types, but is defined) s
+5 646 M
+(   once because of the non-trivial description of the fields and to) s
+5 635 M
+(   ensure maintainability.) s
+5 613 M
+(   The same encoding is used both when returning file attributes from) s
+5 602 M
+(   the server and when sending file attributes to the server.  When) s
+5 591 M
+(   sending it to the server, the flags field specifies which attributes) s
+5 580 M
+(   are included, and the server will use default values for the) s
+5 569 M
+(   remaining attributes \(or will not modify the values of remaining) s
+5 558 M
+(   attributes\).  When receiving attributes from the server, the flags) s
+5 547 M
+(   specify which attributes are included in the returned data.  The) s
+5 536 M
+(   server normally returns all attributes it knows about.) s
+5 514 M
+(        uint32   flags) s
+5 503 M
+(        uint64   size           present only if flag SSH_FILEXFER_ATTR_SIZE) s
+5 492 M
+(        uint32   uid            present only if flag SSH_FILEXFER_ATTR_UIDGID) s
+5 481 M
+(        uint32   gid            present only if flag SSH_FILEXFER_ATTR_UIDGID) s
+5 470 M
+(        uint32   permissions    present only if flag SSH_FILEXFER_ATTR_PERMISSIONS) s
+5 459 M
+(        uint32   atime          present only if flag SSH_FILEXFER_ACMODTIME) s
+5 448 M
+(        uint32   mtime          present only if flag SSH_FILEXFER_ACMODTIME) s
+5 437 M
+(        uint32   extended_count present only if flag SSH_FILEXFER_ATTR_EXTENDED) s
+5 426 M
+(        string   extended_type) s
+5 415 M
+(        string   extended_data) s
+5 404 M
+(        ...      more extended data \(extended_type - extended_data pairs\),) s
+5 393 M
+(                   so that number of pairs equals extended_count) s
+5 371 M
+(   The `flags' specify which of the fields are present.  Those fields) s
+5 360 M
+(   for which the corresponding flag is not set are not present \(not) s
+5 349 M
+(   included in the packet\).  New flags can only be added by incrementing) s
+5 338 M
+(   the protocol version number \(or by using the extension mechanism) s
+5 327 M
+(   described below\).) s
+5 305 M
+(   The `size' field specifies the size of the file in bytes.) s
+5 283 M
+(   The `uid' and `gid' fields contain numeric Unix-like user and group) s
+5 272 M
+(   identifiers, respectively.) s
+5 250 M
+(   The `permissions' field contains a bit mask of file permissions as) s
+5 239 M
+(   defined by posix [1].) s
+5 217 M
+(   The `atime' and `mtime' contain the access and modification times of) s
+5 206 M
+(   the files, respectively.  They are represented as seconds from Jan 1,) s
+5 195 M
+(   1970 in UTC.) s
+5 173 M
+(   The SSH_FILEXFER_ATTR_EXTENDED flag provides a general extension) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                 [Page 8]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (8,9) 5
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 9 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(   mechanism for vendor-specific extensions.  If the flag is specified,) s
+5 679 M
+(   then the `extended_count' field is present.  It specifies the number) s
+5 668 M
+(   of extended_type-extended_data pairs that follow.  Each of these) s
+5 657 M
+(   pairs specifies an extended attribute.  For each of the attributes,) s
+5 646 M
+(   the extended_type field should be a string of the format) s
+5 635 M
+(   "name@domain", where "domain" is a valid, registered domain name and) s
+5 624 M
+(   "name" identifies the method.  The IETF may later standardize certain) s
+5 613 M
+(   names that deviate from this format \(e.g., that do not contain the) s
+5 602 M
+(   "@" sign\).  The interpretation of `extended_data' depends on the) s
+5 591 M
+(   type.  Implementations SHOULD ignore extended data fields that they) s
+5 580 M
+(   do not understand.) s
+5 558 M
+(   Additional fields can be added to the attributes by either defining) s
+5 547 M
+(   additional bits to the flags field to indicate their presence, or by) s
+5 536 M
+(   defining extended attributes for them.  The extended attributes) s
+5 525 M
+(   mechanism is recommended for most purposes; additional flags bits) s
+5 514 M
+(   should only be defined by an IETF standards action that also) s
+5 503 M
+(   increments the protocol version number.  The use of such new fields) s
+5 492 M
+(   MUST be negotiated by the version number in the protocol exchange.) s
+5 481 M
+(   It is a protocol error if a packet with unsupported protocol bits is) s
+5 470 M
+(   received.) s
+5 448 M
+(    The flags bits are defined to have the following values:) s
+5 426 M
+(        #define SSH_FILEXFER_ATTR_SIZE          0x00000001) s
+5 415 M
+(        #define SSH_FILEXFER_ATTR_UIDGID        0x00000002) s
+5 404 M
+(        #define SSH_FILEXFER_ATTR_PERMISSIONS   0x00000004) s
+5 393 M
+(        #define SSH_FILEXFER_ATTR_ACMODTIME     0x00000008) s
+5 382 M
+(        #define SSH_FILEXFER_ATTR_EXTENDED      0x80000000) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                 [Page 9]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 10 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(6. Requests From the Client to the Server) s
+5 668 M
+(   Requests from the client to the server represent the various file) s
+5 657 M
+(   system operations.  Each request begins with an `id' field, which is) s
+5 646 M
+(   a 32-bit identifier identifying the request \(selected by the client\).) s
+5 635 M
+(   The same identifier will be returned in the response to the request.) s
+5 624 M
+(   One possible implementation of it is a monotonically increasing) s
+5 613 M
+(   request sequence number \(modulo 2^32\).) s
+5 591 M
+(   Many operations in the protocol operate on open files.  The) s
+5 580 M
+(   SSH_FXP_OPEN request can return a file handle \(which is an opaque) s
+5 569 M
+(   variable-length string\) which may be used to access the file later) s
+5 558 M
+(   \(e.g.  in a read operation\).  The client MUST NOT send requests the) s
+5 547 M
+(   server with bogus or closed handles.  However, the server MUST) s
+5 536 M
+(   perform adequate checks on the handle in order to avoid security) s
+5 525 M
+(   risks due to fabricated handles.) s
+5 503 M
+(   This design allows either stateful and stateless server) s
+5 492 M
+(   implementation, as well as an implementation which caches state) s
+5 481 M
+(   between requests but may also flush it.  The contents of the file) s
+5 470 M
+(   handle string are entirely up to the server and its design.  The) s
+5 459 M
+(   client should not modify or attempt to interpret the file handle) s
+5 448 M
+(   strings.) s
+5 426 M
+(   The file handle strings MUST NOT be longer than 256 bytes.) s
+5 404 M
+(6.1 Request Synchronization and Reordering) s
+5 382 M
+(   The protocol and implementations MUST process requests relating to) s
+5 371 M
+(   the same file in the order in which they are received.  In other) s
+5 360 M
+(   words, if an application submits multiple requests to the server, the) s
+5 349 M
+(   results in the responses will be the same as if it had sent the) s
+5 338 M
+(   requests one at a time and waited for the response in each case.  For) s
+5 327 M
+(   example, the server may process non-overlapping read/write requests) s
+5 316 M
+(   to the same file in parallel, but overlapping reads and writes cannot) s
+5 305 M
+(   be reordered or parallelized.  However, there are no ordering) s
+5 294 M
+(   restrictions on the server for processing requests from two different) s
+5 283 M
+(   file transfer connections.  The server may interleave and parallelize) s
+5 272 M
+(   them at will.) s
+5 250 M
+(   There are no restrictions on the order in which responses to) s
+5 239 M
+(   outstanding requests are delivered to the client, except that the) s
+5 228 M
+(   server must ensure fairness in the sense that processing of no) s
+5 217 M
+(   request will be indefinitely delayed even if the client is sending) s
+5 206 M
+(   other requests so that there are multiple outstanding requests all) s
+5 195 M
+(   the time.) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 10]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (10,11) 6
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 11 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(6.2 File Names) s
+5 668 M
+(   This protocol represents file names as strings.  File names are) s
+5 657 M
+(   assumed to use the slash \('/'\) character as a directory separator.) s
+5 635 M
+(   File names starting with a slash are "absolute", and are relative to) s
+5 624 M
+(   the root of the file system.  Names starting with any other character) s
+5 613 M
+(   are relative to the user's default directory \(home directory\).  Note) s
+5 602 M
+(   that identifying the user is assumed to take place outside of this) s
+5 591 M
+(   protocol.) s
+5 569 M
+(   Servers SHOULD interpret a path name component ".." as referring to) s
+5 558 M
+(   the parent directory, and "." as referring to the current directory.) s
+5 547 M
+(   If the server implementation limits access to certain parts of the) s
+5 536 M
+(   file system, it must be extra careful in parsing file names when) s
+5 525 M
+(   enforcing such restrictions.  There have been numerous reported) s
+5 514 M
+(   security bugs where a ".." in a path name has allowed access outside) s
+5 503 M
+(   the intended area.) s
+5 481 M
+(   An empty path name is valid, and it refers to the user's default) s
+5 470 M
+(   directory \(usually the user's home directory\).) s
+5 448 M
+(   Otherwise, no syntax is defined for file names by this specification.) s
+5 437 M
+(   Clients should not make any other assumptions; however, they can) s
+5 426 M
+(   splice path name components returned by SSH_FXP_READDIR together) s
+5 415 M
+(   using a slash \('/'\) as the separator, and that will work as expected.) s
+5 393 M
+(   It is understood that the lack of well-defined semantics for file) s
+5 382 M
+(   names may cause interoperability problems between clients and servers) s
+5 371 M
+(   using radically different operating systems.  However, this approach) s
+5 360 M
+(   is known to work acceptably with most systems, and alternative) s
+5 349 M
+(   approaches that e.g.  treat file names as sequences of structured) s
+5 338 M
+(   components are quite complicated.) s
+5 316 M
+(6.3 Opening, Creating, and Closing Files) s
+5 294 M
+(    Files are opened and created using the SSH_FXP_OPEN message, whose) s
+5 283 M
+(   data part is as follows:) s
+5 261 M
+(        uint32        id) s
+5 250 M
+(        string        filename) s
+5 239 M
+(        uint32        pflags) s
+5 228 M
+(        ATTRS         attrs) s
+5 206 M
+(   The `id' field is the request identifier as for all requests.) s
+5 184 M
+(   The `filename' field specifies the file name.  See Section ``File) s
+5 173 M
+(   Names'' for more information.) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 11]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 12 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(    The `pflags' field is a bitmask.  The following bits have been) s
+5 679 M
+(   defined.) s
+5 657 M
+(        #define SSH_FXF_READ            0x00000001) s
+5 646 M
+(        #define SSH_FXF_WRITE           0x00000002) s
+5 635 M
+(        #define SSH_FXF_APPEND          0x00000004) s
+5 624 M
+(        #define SSH_FXF_CREAT           0x00000008) s
+5 613 M
+(        #define SSH_FXF_TRUNC           0x00000010) s
+5 602 M
+(        #define SSH_FXF_EXCL            0x00000020) s
+5 580 M
+(   These have the following meanings:) s
+5 558 M
+(   SSH_FXF_READ) s
+5 547 M
+(      Open the file for reading.) s
+5 525 M
+(   SSH_FXF_WRITE) s
+5 514 M
+(      Open the file for writing.  If both this and SSH_FXF_READ are) s
+5 503 M
+(      specified, the file is opened for both reading and writing.) s
+5 481 M
+(   SSH_FXF_APPEND) s
+5 470 M
+(      Force all writes to append data at the end of the file.) s
+5 448 M
+(   SSH_FXF_CREAT) s
+5 437 M
+(      If this flag is specified, then a new file will be created if one) s
+5 426 M
+(      does not already exist \(if O_TRUNC is specified, the new file will) s
+5 415 M
+(      be truncated to zero length if it previously exists\).) s
+5 393 M
+(   SSH_FXF_TRUNC) s
+5 382 M
+(      Forces an existing file with the same name to be truncated to zero) s
+5 371 M
+(      length when creating a file by specifying SSH_FXF_CREAT.) s
+5 360 M
+(      SSH_FXF_CREAT MUST also be specified if this flag is used.) s
+5 338 M
+(   SSH_FXF_EXCL) s
+5 327 M
+(      Causes the request to fail if the named file already exists.) s
+5 316 M
+(      SSH_FXF_CREAT MUST also be specified if this flag is used.) s
+5 294 M
+(   The `attrs' field specifies the initial attributes for the file.) s
+5 283 M
+(   Default values will be used for those attributes that are not) s
+5 272 M
+(   specified.  See Section ``File Attributes'' for more information.) s
+5 250 M
+(   Regardless the server operating system, the file will always be) s
+5 239 M
+(   opened in "binary" mode \(i.e., no translations between different) s
+5 228 M
+(   character sets and newline encodings\).) s
+5 206 M
+(   The response to this message will be either SSH_FXP_HANDLE \(if the) s
+5 195 M
+(   operation is successful\) or SSH_FXP_STATUS \(if the operation fails\).) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 12]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (12,13) 7
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 13 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(    A file is closed by using the SSH_FXP_CLOSE request.  Its data field) s
+5 679 M
+(   has the following format:) s
+5 657 M
+(        uint32     id) s
+5 646 M
+(        string     handle) s
+5 624 M
+(   where `id' is the request identifier, and `handle' is a handle) s
+5 613 M
+(   previously returned in the response to SSH_FXP_OPEN or) s
+5 602 M
+(   SSH_FXP_OPENDIR.  The handle becomes invalid immediately after this) s
+5 591 M
+(   request has been sent.) s
+5 569 M
+(   The response to this request will be a SSH_FXP_STATUS message.  One) s
+5 558 M
+(   should note that on some server platforms even a close can fail.) s
+5 547 M
+(   This can happen e.g.  if the server operating system caches writes,) s
+5 536 M
+(   and an error occurs while flushing cached writes during the close.) s
+5 514 M
+(6.4 Reading and Writing) s
+5 492 M
+(    Once a file has been opened, it can be read using the SSH_FXP_READ) s
+5 481 M
+(   message, which has the following format:) s
+5 459 M
+(        uint32     id) s
+5 448 M
+(        string     handle) s
+5 437 M
+(        uint64     offset) s
+5 426 M
+(        uint32     len) s
+5 404 M
+(   where `id' is the request identifier, `handle' is an open file handle) s
+5 393 M
+(   returned by SSH_FXP_OPEN, `offset' is the offset \(in bytes\) relative) s
+5 382 M
+(   to the beginning of the file from where to start reading, and `len') s
+5 371 M
+(   is the maximum number of bytes to read.) s
+5 349 M
+(   In response to this request, the server will read as many bytes as it) s
+5 338 M
+(   can from the file \(up to `len'\), and return them in a SSH_FXP_DATA) s
+5 327 M
+(   message.  If an error occurs or EOF is encountered before reading any) s
+5 316 M
+(   data, the server will respond with SSH_FXP_STATUS.  For normal disk) s
+5 305 M
+(   files, it is guaranteed that this will read the specified number of) s
+5 294 M
+(   bytes, or up to end of file.  For e.g.  device files this may return) s
+5 283 M
+(   fewer bytes than requested.) s
+5 261 M
+(    Writing to a file is achieved using the SSH_FXP_WRITE message, which) s
+5 250 M
+(   has the following format:) s
+5 228 M
+(        uint32     id) s
+5 217 M
+(        string     handle) s
+5 206 M
+(        uint64     offset) s
+5 195 M
+(        string     data) s
+5 173 M
+(   where `id' is a request identifier, `handle' is a file handle) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 13]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 14 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(   returned by SSH_FXP_OPEN, `offset' is the offset \(in bytes\) from the) s
+5 679 M
+(   beginning of the file where to start writing, and `data' is the data) s
+5 668 M
+(   to be written.) s
+5 646 M
+(   The write will extend the file if writing beyond the end of the file.) s
+5 635 M
+(   It is legal to write way beyond the end of the file; the semantics) s
+5 624 M
+(   are to write zeroes from the end of the file to the specified offset) s
+5 613 M
+(   and then the data.  On most operating systems, such writes do not) s
+5 602 M
+(   allocate disk space but instead leave "holes" in the file.) s
+5 580 M
+(   The server responds to a write request with a SSH_FXP_STATUS message.) s
+5 558 M
+(6.5 Removing and Renaming Files) s
+5 536 M
+(    Files can be removed using the SSH_FXP_REMOVE message.  It has the) s
+5 525 M
+(   following format:) s
+5 503 M
+(        uint32     id) s
+5 492 M
+(        string     filename) s
+5 470 M
+(   where `id' is the request identifier and `filename' is the name of) s
+5 459 M
+(   the file to be removed.  See Section ``File Names'' for more) s
+5 448 M
+(   information.  This request cannot be used to remove directories.) s
+5 426 M
+(   The server will respond to this request with a SSH_FXP_STATUS) s
+5 415 M
+(   message.) s
+5 393 M
+(    Files \(and directories\) can be renamed using the SSH_FXP_RENAME) s
+5 382 M
+(   message.  Its data is as follows:) s
+5 360 M
+(        uint32     id) s
+5 349 M
+(        string     oldpath) s
+5 338 M
+(        string     newpath) s
+5 316 M
+(   where `id' is the request identifier, `oldpath' is the name of an) s
+5 305 M
+(   existing file or directory, and `newpath' is the new name for the) s
+5 294 M
+(   file or directory.  It is an error if there already exists a file) s
+5 283 M
+(   with the name specified by newpath.  The server may also fail rename) s
+5 272 M
+(   requests in other situations, for example if `oldpath' and `newpath') s
+5 261 M
+(   point to different file systems on the server.) s
+5 239 M
+(   The server will respond to this request with a SSH_FXP_STATUS) s
+5 228 M
+(   message.) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 14]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (14,15) 8
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 15 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(6.6 Creating and Deleting Directories) s
+5 668 M
+(    New directories can be created using the SSH_FXP_MKDIR request.  It) s
+5 657 M
+(   has the following format:) s
+5 635 M
+(        uint32     id) s
+5 624 M
+(        string     path) s
+5 613 M
+(        ATTRS      attrs) s
+5 591 M
+(   where `id' is the request identifier, `path' and `attrs' specifies) s
+5 580 M
+(   the modifications to be made to its attributes.  See Section ``File) s
+5 569 M
+(   Names'' for more information on file names.  Attributes are discussed) s
+5 558 M
+(   in more detail in Section ``File Attributes''.  specifies the) s
+5 547 M
+(   directory to be created.  An error will be returned if a file or) s
+5 536 M
+(   directory with the specified path already exists.  The server will) s
+5 525 M
+(   respond to this request with a SSH_FXP_STATUS message.) s
+5 503 M
+(    Directories can be removed using the SSH_FXP_RMDIR request, which) s
+5 492 M
+(   has the following format:) s
+5 470 M
+(        uint32     id) s
+5 459 M
+(        string     path) s
+5 437 M
+(   where `id' is the request identifier, and `path' specifies the) s
+5 426 M
+(   directory to be removed.  See Section ``File Names'' for more) s
+5 415 M
+(   information on file names.  An error will be returned if no directory) s
+5 404 M
+(   with the specified path exists, or if the specified directory is not) s
+5 393 M
+(   empty, or if the path specified a file system object other than a) s
+5 382 M
+(   directory.  The server responds to this request with a SSH_FXP_STATUS) s
+5 371 M
+(   message.) s
+5 349 M
+(6.7 Scanning Directories) s
+5 327 M
+(   The files in a directory can be listed using the SSH_FXP_OPENDIR and) s
+5 316 M
+(   SSH_FXP_READDIR requests.  Each SSH_FXP_READDIR request returns one) s
+5 305 M
+(   or more file names with full file attributes for each file.  The) s
+5 294 M
+(   client should call SSH_FXP_READDIR repeatedly until it has found the) s
+5 283 M
+(   file it is looking for or until the server responds with a) s
+5 272 M
+(   SSH_FXP_STATUS message indicating an error \(normally SSH_FX_EOF if) s
+5 261 M
+(   there are no more files in the directory\).  The client should then) s
+5 250 M
+(   close the handle using the SSH_FXP_CLOSE request.) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 15]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 16 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(    The SSH_FXP_OPENDIR opens a directory for reading.  It has the) s
+5 679 M
+(   following format:) s
+5 657 M
+(        uint32     id) s
+5 646 M
+(        string     path) s
+5 624 M
+(   where `id' is the request identifier and `path' is the path name of) s
+5 613 M
+(   the directory to be listed \(without any trailing slash\).  See Section) s
+5 602 M
+(   ``File Names'' for more information on file names.  This will return) s
+5 591 M
+(   an error if the path does not specify a directory or if the directory) s
+5 580 M
+(   is not readable.  The server will respond to this request with either) s
+5 569 M
+(   a SSH_FXP_HANDLE or a SSH_FXP_STATUS message.) s
+5 547 M
+(    Once the directory has been successfully opened, files \(and) s
+5 536 M
+(   directories\) contained in it can be listed using SSH_FXP_READDIR) s
+5 525 M
+(   requests.  These are of the format) s
+5 503 M
+(        uint32     id) s
+5 492 M
+(        string     handle) s
+5 470 M
+(   where `id' is the request identifier, and `handle' is a handle) s
+5 459 M
+(   returned by SSH_FXP_OPENDIR.  \(It is a protocol error to attempt to) s
+5 448 M
+(   use an ordinary file handle returned by SSH_FXP_OPEN.\)) s
+5 426 M
+(   The server responds to this request with either a SSH_FXP_NAME or a) s
+5 415 M
+(   SSH_FXP_STATUS message.  One or more names may be returned at a time.) s
+5 404 M
+(   Full status information is returned for each name in order to speed) s
+5 393 M
+(   up typical directory listings.) s
+5 371 M
+(   When the client no longer wishes to read more names from the) s
+5 360 M
+(   directory, it SHOULD call SSH_FXP_CLOSE for the handle.  The handle) s
+5 349 M
+(   should be closed regardless of whether an error has occurred or not.) s
+5 327 M
+(6.8 Retrieving File Attributes) s
+5 305 M
+(   Very often, file attributes are automatically returned by) s
+5 294 M
+(   SSH_FXP_READDIR.  However, sometimes there is need to specifically) s
+5 283 M
+(   retrieve the attributes for a named file.  This can be done using the) s
+5 272 M
+(   SSH_FXP_STAT, SSH_FXP_LSTAT and SSH_FXP_FSTAT requests.) s
+5 250 M
+(    SSH_FXP_STAT and SSH_FXP_LSTAT only differ in that SSH_FXP_STAT) s
+5 239 M
+(   follows symbolic links on the server, whereas SSH_FXP_LSTAT does not) s
+5 228 M
+(   follow symbolic links.  Both have the same format:) s
+5 206 M
+(        uint32     id) s
+5 195 M
+(        string     path) s
+5 173 M
+(   where `id' is the request identifier, and `path' specifies the file) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 16]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (16,17) 9
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 17 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(   system object for which status is to be returned.  The server) s
+5 679 M
+(   responds to this request with either SSH_FXP_ATTRS or SSH_FXP_STATUS.) s
+5 657 M
+(    SSH_FXP_FSTAT differs from the others in that it returns status) s
+5 646 M
+(   information for an open file \(identified by the file handle\).  Its) s
+5 635 M
+(   format is as follows:) s
+5 613 M
+(        uint32     id) s
+5 602 M
+(        string     handle) s
+5 580 M
+(   where `id' is the request identifier and `handle' is a file handle) s
+5 569 M
+(   returned by SSH_FXP_OPEN.  The server responds to this request with) s
+5 558 M
+(   SSH_FXP_ATTRS or SSH_FXP_STATUS.) s
+5 536 M
+(6.9 Setting File Attributes) s
+5 514 M
+(   File attributes may be modified using the SSH_FXP_SETSTAT and) s
+5 503 M
+(   SSH_FXP_FSETSTAT requests.  These requests are used for operations) s
+5 492 M
+(   such as changing the ownership, permissions or access times, as well) s
+5 481 M
+(   as for truncating a file.) s
+5 459 M
+(    The SSH_FXP_SETSTAT request is of the following format:) s
+5 437 M
+(        uint32     id) s
+5 426 M
+(        string     path) s
+5 415 M
+(        ATTRS      attrs) s
+5 393 M
+(   where `id' is the request identifier, `path' specifies the file) s
+5 382 M
+(   system object \(e.g.  file or directory\) whose attributes are to be) s
+5 371 M
+(   modified, and `attrs' specifies the modifications to be made to its) s
+5 360 M
+(   attributes.  Attributes are discussed in more detail in Section) s
+5 349 M
+(   ``File Attributes''.) s
+5 327 M
+(   An error will be returned if the specified file system object does) s
+5 316 M
+(   not exist or the user does not have sufficient rights to modify the) s
+5 305 M
+(   specified attributes.  The server responds to this request with a) s
+5 294 M
+(   SSH_FXP_STATUS message.) s
+5 272 M
+(    The SSH_FXP_FSETSTAT request modifies the attributes of a file which) s
+5 261 M
+(   is already open.  It has the following format:) s
+5 239 M
+(        uint32     id) s
+5 228 M
+(        string     handle) s
+5 217 M
+(        ATTRS      attrs) s
+5 195 M
+(   where `id' is the request identifier, `handle' \(MUST be returned by) s
+5 184 M
+(   SSH_FXP_OPEN\) identifies the file whose attributes are to be) s
+5 173 M
+(   modified, and `attrs' specifies the modifications to be made to its) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 17]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 18 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(   attributes.  Attributes are discussed in more detail in Section) s
+5 679 M
+(   ``File Attributes''.  The server will respond to this request with) s
+5 668 M
+(   SSH_FXP_STATUS.) s
+5 646 M
+(6.10 Dealing with Symbolic links) s
+5 624 M
+(    The SSH_FXP_READLINK request may be used to read the target of a) s
+5 613 M
+(   symbolic link.  It would have a data part as follows:) s
+5 591 M
+(        uint32     id) s
+5 580 M
+(        string     path) s
+5 558 M
+(   where `id' is the request identifier and `path' specifies the path) s
+5 547 M
+(   name of the symlink to be read.) s
+5 525 M
+(   The server will respond with a SSH_FXP_NAME packet containing only) s
+5 514 M
+(   one name and a dummy attributes value.  The name in the returned) s
+5 503 M
+(   packet contains the target of the link.  If an error occurs, the) s
+5 492 M
+(   server may respond with SSH_FXP_STATUS.) s
+5 470 M
+(    The SSH_FXP_SYMLINK request will create a symbolic link on the) s
+5 459 M
+(   server.  It is of the following format) s
+5 437 M
+(        uint32     id) s
+5 426 M
+(        string     linkpath) s
+5 415 M
+(        string     targetpath) s
+5 393 M
+(   where `id' is the request identifier, `linkpath' specifies the path) s
+5 382 M
+(   name of the symlink to be created and `targetpath' specifies the) s
+5 371 M
+(   target of the symlink.  The server shall respond with a) s
+5 360 M
+(   SSH_FXP_STATUS indicating either success \(SSH_FX_OK\) or an error) s
+5 349 M
+(   condition.) s
+5 327 M
+(6.11 Canonicalizing the Server-Side Path Name) s
+5 305 M
+(    The SSH_FXP_REALPATH request can be used to have the server) s
+5 294 M
+(   canonicalize any given path name to an absolute path.  This is useful) s
+5 283 M
+(   for converting path names containing ".." components or relative) s
+5 272 M
+(   pathnames without a leading slash into absolute paths.  The format of) s
+5 261 M
+(   the request is as follows:) s
+5 239 M
+(        uint32     id) s
+5 228 M
+(        string     path) s
+5 206 M
+(   where `id' is the request identifier and `path' specifies the path) s
+5 195 M
+(   name to be canonicalized.  The server will respond with a) s
+5 184 M
+(   SSH_FXP_NAME packet containing only one name and a dummy attributes) s
+5 173 M
+(   value.  The name is the returned packet will be in canonical form.) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 18]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (18,19) 10
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 19 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(   If an error occurs, the server may also respond with SSH_FXP_STATUS.) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 19]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 20 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(7. Responses from the Server to the Client) s
+5 668 M
+(   The server responds to the client using one of a few response) s
+5 657 M
+(   packets.  All requests can return a SSH_FXP_STATUS response upon) s
+5 646 M
+(   failure.  When the operation is successful, any of the responses may) s
+5 635 M
+(   be returned \(depending on the operation\).  If no data needs to be) s
+5 624 M
+(   returned to the client, the SSH_FXP_STATUS response with SSH_FX_OK) s
+5 613 M
+(   status is appropriate.  Otherwise, the SSH_FXP_HANDLE message is used) s
+5 602 M
+(   to return a file handle \(for SSH_FXP_OPEN and SSH_FXP_OPENDIR) s
+5 591 M
+(   requests\), SSH_FXP_DATA is used to return data from SSH_FXP_READ,) s
+5 580 M
+(   SSH_FXP_NAME is used to return one or more file names from a) s
+5 569 M
+(   SSH_FXP_READDIR or SSH_FXP_REALPATH request, and SSH_FXP_ATTRS is) s
+5 558 M
+(   used to return file attributes from SSH_FXP_STAT, SSH_FXP_LSTAT, and) s
+5 547 M
+(   SSH_FXP_FSTAT requests.) s
+5 525 M
+(   Exactly one response will be returned for each request.  Each) s
+5 514 M
+(   response packet contains a request identifier which can be used to) s
+5 503 M
+(   match each response with the corresponding request.  Note that it is) s
+5 492 M
+(   legal to have several requests outstanding simultaneously, and the) s
+5 481 M
+(   server is allowed to send responses to them in a different order from) s
+5 470 M
+(   the order in which the requests were sent \(the result of their) s
+5 459 M
+(   execution, however, is guaranteed to be as if they had been processed) s
+5 448 M
+(   one at a time in the order in which the requests were sent\).) s
+5 426 M
+(   Response packets are of the same general format as request packets.) s
+5 415 M
+(   Each response packet begins with the request identifier.) s
+5 393 M
+(    The format of the data portion of the SSH_FXP_STATUS response is as) s
+5 382 M
+(   follows:) s
+5 360 M
+(        uint32     id) s
+5 349 M
+(        uint32     error/status code) s
+5 338 M
+(        string     error message \(ISO-10646 UTF-8 [RFC-2279]\)) s
+5 327 M
+(        string     language tag \(as defined in [RFC-1766]\)) s
+5 305 M
+(   where `id' is the request identifier, and `error/status code') s
+5 294 M
+(   indicates the result of the requested operation.  The value SSH_FX_OK) s
+5 283 M
+(   indicates success, and all other values indicate failure.) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 20]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (20,21) 11
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 21 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(    Currently, the following values are defined \(other values may be) s
+5 679 M
+(   defined by future versions of this protocol\):) s
+5 657 M
+(        #define SSH_FX_OK                            0) s
+5 646 M
+(        #define SSH_FX_EOF                           1) s
+5 635 M
+(        #define SSH_FX_NO_SUCH_FILE                  2) s
+5 624 M
+(        #define SSH_FX_PERMISSION_DENIED             3) s
+5 613 M
+(        #define SSH_FX_FAILURE                       4) s
+5 602 M
+(        #define SSH_FX_BAD_MESSAGE                   5) s
+5 591 M
+(        #define SSH_FX_NO_CONNECTION                 6) s
+5 580 M
+(        #define SSH_FX_CONNECTION_LOST               7) s
+5 569 M
+(        #define SSH_FX_OP_UNSUPPORTED                8) s
+5 547 M
+(   SSH_FX_OK) s
+5 536 M
+(      Indicates successful completion of the operation.) s
+5 514 M
+(   SSH_FX_EOF) s
+5 503 M
+(      indicates end-of-file condition; for SSH_FX_READ it means that no) s
+5 492 M
+(      more data is available in the file, and for SSH_FX_READDIR it) s
+5 481 M
+(      indicates that no more files are contained in the directory.) s
+5 459 M
+(   SSH_FX_NO_SUCH_FILE) s
+5 448 M
+(      is returned when a reference is made to a file which should exist) s
+5 437 M
+(      but doesn't.) s
+5 415 M
+(   SSH_FX_PERMISSION_DENIED) s
+5 404 M
+(      is returned when the authenticated user does not have sufficient) s
+5 393 M
+(      permissions to perform the operation.) s
+5 371 M
+(   SSH_FX_FAILURE) s
+5 360 M
+(      is a generic catch-all error message; it should be returned if an) s
+5 349 M
+(      error occurs for which there is no more specific error code) s
+5 338 M
+(      defined.) s
+5 316 M
+(   SSH_FX_BAD_MESSAGE) s
+5 305 M
+(      may be returned if a badly formatted packet or protocol) s
+5 294 M
+(      incompatibility is detected.) s
+5 272 M
+(   SSH_FX_NO_CONNECTION) s
+5 261 M
+(      is a pseudo-error which indicates that the client has no) s
+5 250 M
+(      connection to the server \(it can only be generated locally by the) s
+5 239 M
+(      client, and MUST NOT be returned by servers\).) s
+5 217 M
+(   SSH_FX_CONNECTION_LOST) s
+5 206 M
+(      is a pseudo-error which indicates that the connection to the) s
+5 195 M
+(      server has been lost \(it can only be generated locally by the) s
+5 184 M
+(      client, and MUST NOT be returned by servers\).) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 21]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 22 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(   SSH_FX_OP_UNSUPPORTED) s
+5 679 M
+(      indicates that an attempt was made to perform an operation which) s
+5 668 M
+(      is not supported for the server \(it may be generated locally by) s
+5 657 M
+(      the client if e.g.  the version number exchange indicates that a) s
+5 646 M
+(      required feature is not supported by the server, or it may be) s
+5 635 M
+(      returned by the server if the server does not implement an) s
+5 624 M
+(      operation\).) s
+5 602 M
+(   The SSH_FXP_HANDLE response has the following format:) s
+5 580 M
+(        uint32     id) s
+5 569 M
+(        string     handle) s
+5 547 M
+(   where `id' is the request identifier, and `handle' is an arbitrary) s
+5 536 M
+(   string that identifies an open file or directory on the server.  The) s
+5 525 M
+(   handle is opaque to the client; the client MUST NOT attempt to) s
+5 514 M
+(   interpret or modify it in any way.  The length of the handle string) s
+5 503 M
+(   MUST NOT exceed 256 data bytes.) s
+5 481 M
+(    The SSH_FXP_DATA response has the following format:) s
+5 459 M
+(        uint32     id) s
+5 448 M
+(        string     data) s
+5 426 M
+(   where `id' is the request identifier, and `data' is an arbitrary byte) s
+5 415 M
+(   string containing the requested data.  The data string may be at most) s
+5 404 M
+(   the number of bytes requested in a SSH_FXP_READ request, but may also) s
+5 393 M
+(   be shorter if end of file is reached or if the read is from something) s
+5 382 M
+(   other than a regular file.) s
+5 360 M
+(    The SSH_FXP_NAME response has the following format:) s
+5 338 M
+(        uint32     id) s
+5 327 M
+(        uint32     count) s
+5 316 M
+(        repeats count times:) s
+5 305 M
+(                string     filename) s
+5 294 M
+(                string     longname) s
+5 283 M
+(                ATTRS      attrs) s
+5 261 M
+(   where `id' is the request identifier, `count' is the number of names) s
+5 250 M
+(   returned in this response, and the remaining fields repeat `count') s
+5 239 M
+(   times \(so that all three fields are first included for the first) s
+5 228 M
+(   file, then for the second file, etc\).  In the repeated part,) s
+5 217 M
+(   `filename' is a file name being returned \(for SSH_FXP_READDIR, it) s
+5 206 M
+(   will be a relative name within the directory, without any path) s
+5 195 M
+(   components; for SSH_FXP_REALPATH it will be an absolute path name\),) s
+5 184 M
+(   `longname' is an expanded format for the file name, similar to what) s
+5 173 M
+(   is returned by "ls -l" on Unix systems, and `attrs' is the attributes) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 22]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (22,23) 12
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 23 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(   of the file as described in Section ``File Attributes''.) s
+5 668 M
+(   The format of the `longname' field is unspecified by this protocol.) s
+5 657 M
+(   It MUST be suitable for use in the output of a directory listing) s
+5 646 M
+(   command \(in fact, the recommended operation for a directory listing) s
+5 635 M
+(   command is to simply display this data\).  However, clients SHOULD NOT) s
+5 624 M
+(   attempt to parse the longname field for file attributes; they SHOULD) s
+5 613 M
+(   use the attrs field instead.) s
+5 591 M
+(    The recommended format for the longname field is as follows:) s
+5 569 M
+(        -rwxr-xr-x   1 mjos     staff      348911 Mar 25 14:29 t-filexfer) s
+5 558 M
+(        1234567890 123 12345678 12345678 12345678 123456789012) s
+5 536 M
+(   Here, the first line is sample output, and the second field indicates) s
+5 525 M
+(   widths of the various fields.  Fields are separated by spaces.  The) s
+5 514 M
+(   first field lists file permissions for user, group, and others; the) s
+5 503 M
+(   second field is link count; the third field is the name of the user) s
+5 492 M
+(   who owns the file; the fourth field is the name of the group that) s
+5 481 M
+(   owns the file; the fifth field is the size of the file in bytes; the) s
+5 470 M
+(   sixth field \(which actually may contain spaces, but is fixed to 12) s
+5 459 M
+(   characters\) is the file modification time, and the seventh field is) s
+5 448 M
+(   the file name.  Each field is specified to be a minimum of certain) s
+5 437 M
+(   number of character positions \(indicated by the second line above\),) s
+5 426 M
+(   but may also be longer if the data does not fit in the specified) s
+5 415 M
+(   length.) s
+5 393 M
+(    The SSH_FXP_ATTRS response has the following format:) s
+5 371 M
+(        uint32     id) s
+5 360 M
+(        ATTRS      attrs) s
+5 338 M
+(   where `id' is the request identifier, and `attrs' is the returned) s
+5 327 M
+(   file attributes as described in Section ``File Attributes''.) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 23]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 24 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(8. Vendor-Specific Extensions) s
+5 668 M
+(    The SSH_FXP_EXTENDED request provides a generic extension mechanism) s
+5 657 M
+(   for adding vendor-specific commands.  The request has the following) s
+5 646 M
+(   format:) s
+5 624 M
+(        uint32     id) s
+5 613 M
+(        string     extended-request) s
+5 602 M
+(        ... any request-specific data ...) s
+5 580 M
+(   where `id' is the request identifier, and `extended-request' is a) s
+5 569 M
+(   string of the format "name@domain", where domain is an internet) s
+5 558 M
+(   domain name of the vendor defining the request.  The rest of the) s
+5 547 M
+(   request is completely vendor-specific, and servers should only) s
+5 536 M
+(   attempt to interpret it if they recognize the `extended-request') s
+5 525 M
+(   name.) s
+5 503 M
+(   The server may respond to such requests using any of the response) s
+5 492 M
+(   packets defined in Section ``Responses from the Server to the) s
+5 481 M
+(   Client''.  Additionally, the server may also respond with a) s
+5 470 M
+(   SSH_FXP_EXTENDED_REPLY packet, as defined below.  If the server does) s
+5 459 M
+(   not recognize the `extended-request' name, then the server MUST) s
+5 448 M
+(   respond with SSH_FXP_STATUS with error/status set to) s
+5 437 M
+(   SSH_FX_OP_UNSUPPORTED.) s
+5 415 M
+(    The SSH_FXP_EXTENDED_REPLY packet can be used to carry arbitrary) s
+5 404 M
+(   extension-specific data from the server to the client.  It is of the) s
+5 393 M
+(   following format:) s
+5 371 M
+(        uint32     id) s
+5 360 M
+(        ... any request-specific data ...) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 24]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (24,25) 13
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 25 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(9. Security Considerations) s
+5 668 M
+(   This protocol assumes that it is run over a secure channel and that) s
+5 657 M
+(   the endpoints of the channel have been authenticated.  Thus, this) s
+5 646 M
+(   protocol assumes that it is externally protected from network-level) s
+5 635 M
+(   attacks.) s
+5 613 M
+(   This protocol provides file system access to arbitrary files on the) s
+5 602 M
+(   server \(only constrained by the server implementation\).  It is the) s
+5 591 M
+(   responsibility of the server implementation to enforce any access) s
+5 580 M
+(   controls that may be required to limit the access allowed for any) s
+5 569 M
+(   particular user \(the user being authenticated externally to this) s
+5 558 M
+(   protocol, typically using the SSH User Authentication Protocol [6].) s
+5 536 M
+(   Care must be taken in the server implementation to check the validity) s
+5 525 M
+(   of received file handle strings.  The server should not rely on them) s
+5 514 M
+(   directly; it MUST check the validity of each handle before relying on) s
+5 503 M
+(   it.) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 25]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 26 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(10. Changes from previous protocol versions) s
+5 668 M
+(   The SSH File Transfer Protocol has changed over time, before it's) s
+5 657 M
+(   standardization.  The following is a description of the incompatible) s
+5 646 M
+(   changes between different versions.) s
+5 624 M
+(10.1 Changes between versions 3 and 2) s
+5 602 M
+(   o  The SSH_FXP_READLINK and SSH_FXP_SYMLINK messages were added.) s
+5 580 M
+(   o  The SSH_FXP_EXTENDED and SSH_FXP_EXTENDED_REPLY messages were) s
+5 569 M
+(      added.) s
+5 547 M
+(   o  The SSH_FXP_STATUS message was changed to include fields `error) s
+5 536 M
+(      message' and `language tag'.) s
+5 503 M
+(10.2 Changes between versions 2 and 1) s
+5 481 M
+(   o  The SSH_FXP_RENAME message was added.) s
+5 448 M
+(10.3 Changes between versions 1 and 0) s
+5 426 M
+(   o  Implementation changes, no actual protocol changes.) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 26]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (26,27) 14
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 27 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(11. Trademark Issues) s
+5 668 M
+(   "ssh" is a registered trademark of SSH Communications Security Corp) s
+5 657 M
+(   in the United States and/or other countries.) s
+5 129 M
+(Ylonen & Lehtinen         Expires April 1, 2002                [Page 27]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 28 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2001) s
+5 690 M
+(References) s
+5 668 M
+(   [1]  Dierks, T., Allen, C., Treese, W., Karlton, P., Freier, A. and) s
+5 657 M
+(        P. Kocher, "The TLS Protocol Version 1.0", RFC 2246, January) s
+5 646 M
+(        1999.) s
+5 624 M
+(   [2]  Institute of Electrical and Electronics Engineers, "Information) s
+5 613 M
+(        Technology - Portable Operating System Interface \(POSIX\) - Part) s
+5 602 M
+(        1: System Application Program Interface \(API\) [C Language]",) s
+5 591 M
+(        IEEE Standard 1003.2, 1996.) s
+5 569 M
+(   [3]  Rinne, T., Ylonen, T., Kivinen, T., Saarinen, M. and S.) s
+5 558 M
+(        Lehtinen, "SSH Protocol Architecture", draft-ietf-secsh-) s
+5 547 M
+(        architecture-09 \(work in progress\), July 2001.) s
+5 525 M
+(   [4]  Rinne, T., Ylonen, T., Kivinen, T., Saarinen, M. and S.) s
+5 514 M
+(        Lehtinen, "SSH Protocol Transport Protocol", draft-ietf-secsh-) s
+5 503 M
+(        architecture-09 \(work in progress\), July 2001.) s
+5 481 M
+(   [5]  Rinne, T., Ylonen, T., Kivinen, T., Saarinen, M. and S.) s
+5 470 M
+(        Lehtinen, "SSH Connection Protocol", draft-ietf-secsh-connect-11) s
+5 459 M
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+5 437 M
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diff --git a/lib/ssh/doc/standard/draft-ietf-secsh-filexfer-02.txt b/lib/ssh/doc/standard/draft-ietf-secsh-filexfer-02.txt
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+
+
+
+Network Working Group                                          T. Ylonen
+Internet-Draft                                               S. Lehtinen
+Expires: April 1, 2002                  SSH Communications Security Corp
+                                                            October 2001
+
+
+                       SSH File Transfer Protocol
+                    draft-ietf-secsh-filexfer-02.txt
+
+Status of this Memo
+
+   This document is an Internet-Draft and is in full conformance with
+   all provisions of Section 10 of RFC2026.
+
+   Internet-Drafts are working documents of the Internet Engineering
+   Task Force (IETF), its areas, and its working groups.  Note that
+   other groups may also distribute working documents as Internet-
+   Drafts.
+
+   Internet-Drafts are draft documents valid for a maximum of six months
+   and may be updated, replaced, or obsoleted by other documents at any
+   time.  It is inappropriate to use Internet-Drafts as reference
+   material or to cite them other than as "work in progress."
+
+   The list of current Internet-Drafts can be accessed at http://
+   www.ietf.org/ietf/1id-abstracts.txt.
+
+   The list of Internet-Draft Shadow Directories can be accessed at
+   http://www.ietf.org/shadow.html.
+
+   This Internet-Draft will expire on April 1, 2002.
+
+Copyright Notice
+
+   Copyright (C) The Internet Society (2001).  All Rights Reserved.
+
+Abstract
+
+   The SSH File Transfer Protocol provides secure file transfer
+   functionality over any reliable data stream.  It is the standard file
+   transfer protocol for use with the SSH2 protocol.  This document
+   describes the file transfer protocol and its interface to the SSH2
+   protocol suite.
+
+
+
+
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                 [Page 1]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+Table of Contents
+
+   1.   Introduction . . . . . . . . . . . . . . . . . . . . . . . .   3
+   2.   Use with the SSH Connection Protocol . . . . . . . . . . . .   4
+   3.   General Packet Format  . . . . . . . . . . . . . . . . . . .   5
+   4.   Protocol Initialization  . . . . . . . . . . . . . . . . . .   7
+   5.   File Attributes  . . . . . . . . . . . . . . . . . . . . . .   8
+   6.   Requests From the Client to the Server . . . . . . . . . . .  10
+   6.1  Request Synchronization and Reordering . . . . . . . . . . .  10
+   6.2  File Names . . . . . . . . . . . . . . . . . . . . . . . . .  11
+   6.3  Opening, Creating, and Closing Files . . . . . . . . . . . .  11
+   6.4  Reading and Writing  . . . . . . . . . . . . . . . . . . . .  13
+   6.5  Removing and Renaming Files  . . . . . . . . . . . . . . . .  14
+   6.6  Creating and Deleting Directories  . . . . . . . . . . . . .  15
+   6.7  Scanning Directories . . . . . . . . . . . . . . . . . . . .  15
+   6.8  Retrieving File Attributes . . . . . . . . . . . . . . . . .  16
+   6.9  Setting File Attributes  . . . . . . . . . . . . . . . . . .  17
+   6.10 Dealing with Symbolic links  . . . . . . . . . . . . . . . .  18
+   6.11 Canonicalizing the Server-Side Path Name . . . . . . . . . .  18
+   7.   Responses from the Server to the Client  . . . . . . . . . .  20
+   8.   Vendor-Specific Extensions . . . . . . . . . . . . . . . . .  24
+   9.   Security Considerations  . . . . . . . . . . . . . . . . . .  25
+   10.  Changes from previous protocol versions  . . . . . . . . . .  26
+   10.1 Changes between versions 3 and 2 . . . . . . . . . . . . . .  26
+   10.2 Changes between versions 2 and 1 . . . . . . . . . . . . . .  26
+   10.3 Changes between versions 1 and 0 . . . . . . . . . . . . . .  26
+   11.  Trademark Issues . . . . . . . . . . . . . . . . . . . . . .  27
+        References . . . . . . . . . . . . . . . . . . . . . . . . .  28
+        Authors' Addresses . . . . . . . . . . . . . . . . . . . . .  28
+        Full Copyright Statement . . . . . . . . . . . . . . . . . .  29
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                 [Page 2]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+1. Introduction
+
+   This protocol provides secure file transfer (and more generally file
+   system access) functionality over a reliable data stream, such as a
+   channel in the SSH2 protocol [3].
+
+   This protocol is designed so that it could be used to implement a
+   secure remote file system service, as well as a secure file transfer
+   service.
+
+   This protocol assumes that it runs over a secure channel, and that
+   the server has already authenticated the user at the client end, and
+   that the identity of the client user is externally available to the
+   server implementation.
+
+   In general, this protocol follows a simple request-response model.
+   Each request and response contains a sequence number and multiple
+   requests may be pending simultaneously.  There are a relatively large
+   number of different request messages, but a small number of possible
+   response messages.  Each request has one or more response messages
+   that may be returned in result (e.g., a read either returns data or
+   reports error status).
+
+   The packet format descriptions in this specification follow the
+   notation presented in the secsh architecture draft.[3].
+
+   Even though this protocol is described in the context of the SSH2
+   protocol, this protocol is general and independent of the rest of the
+   SSH2 protocol suite.  It could be used in a number of different
+   applications, such as secure file transfer over TLS RFC 2246 [1] and
+   transfer of management information in VPN applications.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                 [Page 3]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+2. Use with the SSH Connection Protocol
+
+   When used with the SSH2 Protocol suite, this protocol is intended to
+   be used from the SSH Connection Protocol [5] as a subsystem, as
+   described in section ``Starting a Shell or a Command''.  The
+   subsystem name used with this protocol is "sftp".
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
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+
+
+
+
+
+
+
+
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+
+
+Ylonen & Lehtinen         Expires April 1, 2002                 [Page 4]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+3. General Packet Format
+
+    All packets transmitted over the secure connection are of the
+   following format:
+
+   	uint32             length
+   	byte               type
+   	byte[length - 1]   data payload
+
+   That is, they are just data preceded by 32-bit length and 8-bit type
+   fields.  The `length' is the length of the data area, and does not
+   include the `length' field itself.  The format and interpretation of
+   the data area depends on the packet type.
+
+   All packet descriptions below only specify the packet type and the
+   data that goes into the data field.  Thus, they should be prefixed by
+   the `length' and `type' fields.
+
+   The maximum size of a packet is in practice determined by the client
+   (the maximum size of read or write requests that it sends, plus a few
+   bytes of packet overhead).  All servers SHOULD support packets of at
+   least 34000 bytes (where the packet size refers to the full length,
+   including the header above).  This should allow for reads and writes
+   of at most 32768 bytes.
+
+   There is no limit on the number of outstanding (non-acknowledged)
+   requests that the client may send to the server.  In practice this is
+   limited by the buffering available on the data stream and the queuing
+   performed by the server.  If the server's queues are full, it should
+   not read any more data from the stream, and flow control will prevent
+   the client from sending more requests.  Note, however, that while
+   there is no restriction on the protocol level, the client's API may
+   provide a limit in order to prevent infinite queuing of outgoing
+   requests at the client.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                 [Page 5]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+   The following values are defined for packet types.
+
+   	#define SSH_FXP_INIT                1
+   	#define SSH_FXP_VERSION             2
+   	#define SSH_FXP_OPEN                3
+   	#define SSH_FXP_CLOSE               4
+   	#define SSH_FXP_READ                5
+   	#define SSH_FXP_WRITE               6
+   	#define SSH_FXP_LSTAT               7
+   	#define SSH_FXP_FSTAT               8
+   	#define SSH_FXP_SETSTAT             9
+   	#define SSH_FXP_FSETSTAT           10
+   	#define SSH_FXP_OPENDIR            11
+   	#define SSH_FXP_READDIR            12
+   	#define SSH_FXP_REMOVE             13
+   	#define SSH_FXP_MKDIR              14
+   	#define SSH_FXP_RMDIR              15
+   	#define SSH_FXP_REALPATH           16
+   	#define SSH_FXP_STAT               17
+   	#define SSH_FXP_RENAME             18
+   	#define SSH_FXP_READLINK           19
+   	#define SSH_FXP_SYMLINK            20
+   	#define SSH_FXP_STATUS            101
+   	#define SSH_FXP_HANDLE            102
+   	#define SSH_FXP_DATA              103
+   	#define SSH_FXP_NAME              104
+   	#define SSH_FXP_ATTRS             105
+   	#define SSH_FXP_EXTENDED          200
+   	#define SSH_FXP_EXTENDED_REPLY    201
+
+   Additional packet types should only be defined if the protocol
+   version number (see Section ``Protocol Initialization'') is
+   incremented, and their use MUST be negotiated using the version
+   number.  However, the SSH_FXP_EXTENDED and SSH_FXP_EXTENDED_REPLY
+   packets can be used to implement vendor-specific extensions.  See
+   Section ``Vendor-Specific-Extensions'' for more details.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                 [Page 6]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+4. Protocol Initialization
+
+   When the file transfer protocol starts, it first sends a SSH_FXP_INIT
+   (including its version number) packet to the server.  The server
+   responds with a SSH_FXP_VERSION packet, supplying the lowest of its
+   own and the client's version number.  Both parties should from then
+   on adhere to particular version of the protocol.
+
+   The SSH_FXP_INIT packet (from client to server) has the following
+   data:
+
+   	uint32 version
+   	<extension data>
+
+    The SSH_FXP_VERSION packet (from server to client) has the following
+   data:
+
+   	uint32 version
+   	<extension data>
+
+   The version number of the protocol specified in this document is 3.
+   The version number should be incremented for each incompatible
+   revision of this protocol.
+
+    The extension data in the above packets may be empty, or may be a
+   sequence of
+
+   	string extension_name
+   	string extension_data
+
+   pairs (both strings MUST always be present if one is, but the
+   `extension_data' string may be of zero length).  If present, these
+   strings indicate extensions to the baseline protocol.  The
+   `extension_name' field(s) identify the name of the extension.  The
+   name should be of the form "name@domain", where the domain is the DNS
+   domain name of the organization defining the extension.  Additional
+   names that are not of this format may be defined later by the IETF.
+   Implementations MUST silently ignore any extensions whose name they
+   do not recognize.
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                 [Page 7]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+5. File Attributes
+
+   A new compound data type is defined for encoding file attributes.  It
+   is basically just a combination of elementary types, but is defined
+   once because of the non-trivial description of the fields and to
+   ensure maintainability.
+
+   The same encoding is used both when returning file attributes from
+   the server and when sending file attributes to the server.  When
+   sending it to the server, the flags field specifies which attributes
+   are included, and the server will use default values for the
+   remaining attributes (or will not modify the values of remaining
+   attributes).  When receiving attributes from the server, the flags
+   specify which attributes are included in the returned data.  The
+   server normally returns all attributes it knows about.
+
+   	uint32   flags
+   	uint64   size           present only if flag SSH_FILEXFER_ATTR_SIZE
+   	uint32   uid            present only if flag SSH_FILEXFER_ATTR_UIDGID
+   	uint32   gid            present only if flag SSH_FILEXFER_ATTR_UIDGID
+   	uint32   permissions    present only if flag SSH_FILEXFER_ATTR_PERMISSIONS
+   	uint32   atime          present only if flag SSH_FILEXFER_ACMODTIME
+   	uint32   mtime          present only if flag SSH_FILEXFER_ACMODTIME
+   	uint32   extended_count present only if flag SSH_FILEXFER_ATTR_EXTENDED
+   	string   extended_type
+   	string   extended_data
+   	...      more extended data (extended_type - extended_data pairs),
+   		   so that number of pairs equals extended_count
+
+   The `flags' specify which of the fields are present.  Those fields
+   for which the corresponding flag is not set are not present (not
+   included in the packet).  New flags can only be added by incrementing
+   the protocol version number (or by using the extension mechanism
+   described below).
+
+   The `size' field specifies the size of the file in bytes.
+
+   The `uid' and `gid' fields contain numeric Unix-like user and group
+   identifiers, respectively.
+
+   The `permissions' field contains a bit mask of file permissions as
+   defined by posix [1].
+
+   The `atime' and `mtime' contain the access and modification times of
+   the files, respectively.  They are represented as seconds from Jan 1,
+   1970 in UTC.
+
+   The SSH_FILEXFER_ATTR_EXTENDED flag provides a general extension
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                 [Page 8]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+   mechanism for vendor-specific extensions.  If the flag is specified,
+   then the `extended_count' field is present.  It specifies the number
+   of extended_type-extended_data pairs that follow.  Each of these
+   pairs specifies an extended attribute.  For each of the attributes,
+   the extended_type field should be a string of the format
+   "name@domain", where "domain" is a valid, registered domain name and
+   "name" identifies the method.  The IETF may later standardize certain
+   names that deviate from this format (e.g., that do not contain the
+   "@" sign).  The interpretation of `extended_data' depends on the
+   type.  Implementations SHOULD ignore extended data fields that they
+   do not understand.
+
+   Additional fields can be added to the attributes by either defining
+   additional bits to the flags field to indicate their presence, or by
+   defining extended attributes for them.  The extended attributes
+   mechanism is recommended for most purposes; additional flags bits
+   should only be defined by an IETF standards action that also
+   increments the protocol version number.  The use of such new fields
+   MUST be negotiated by the version number in the protocol exchange.
+   It is a protocol error if a packet with unsupported protocol bits is
+   received.
+
+    The flags bits are defined to have the following values:
+
+   	#define SSH_FILEXFER_ATTR_SIZE          0x00000001
+   	#define SSH_FILEXFER_ATTR_UIDGID        0x00000002
+   	#define SSH_FILEXFER_ATTR_PERMISSIONS   0x00000004
+   	#define SSH_FILEXFER_ATTR_ACMODTIME     0x00000008
+   	#define SSH_FILEXFER_ATTR_EXTENDED      0x80000000
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                 [Page 9]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+6. Requests From the Client to the Server
+
+   Requests from the client to the server represent the various file
+   system operations.  Each request begins with an `id' field, which is
+   a 32-bit identifier identifying the request (selected by the client).
+   The same identifier will be returned in the response to the request.
+   One possible implementation of it is a monotonically increasing
+   request sequence number (modulo 2^32).
+
+   Many operations in the protocol operate on open files.  The
+   SSH_FXP_OPEN request can return a file handle (which is an opaque
+   variable-length string) which may be used to access the file later
+   (e.g.  in a read operation).  The client MUST NOT send requests the
+   server with bogus or closed handles.  However, the server MUST
+   perform adequate checks on the handle in order to avoid security
+   risks due to fabricated handles.
+
+   This design allows either stateful and stateless server
+   implementation, as well as an implementation which caches state
+   between requests but may also flush it.  The contents of the file
+   handle string are entirely up to the server and its design.  The
+   client should not modify or attempt to interpret the file handle
+   strings.
+
+   The file handle strings MUST NOT be longer than 256 bytes.
+
+6.1 Request Synchronization and Reordering
+
+   The protocol and implementations MUST process requests relating to
+   the same file in the order in which they are received.  In other
+   words, if an application submits multiple requests to the server, the
+   results in the responses will be the same as if it had sent the
+   requests one at a time and waited for the response in each case.  For
+   example, the server may process non-overlapping read/write requests
+   to the same file in parallel, but overlapping reads and writes cannot
+   be reordered or parallelized.  However, there are no ordering
+   restrictions on the server for processing requests from two different
+   file transfer connections.  The server may interleave and parallelize
+   them at will.
+
+   There are no restrictions on the order in which responses to
+   outstanding requests are delivered to the client, except that the
+   server must ensure fairness in the sense that processing of no
+   request will be indefinitely delayed even if the client is sending
+   other requests so that there are multiple outstanding requests all
+   the time.
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 10]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+6.2 File Names
+
+   This protocol represents file names as strings.  File names are
+   assumed to use the slash ('/') character as a directory separator.
+
+   File names starting with a slash are "absolute", and are relative to
+   the root of the file system.  Names starting with any other character
+   are relative to the user's default directory (home directory).  Note
+   that identifying the user is assumed to take place outside of this
+   protocol.
+
+   Servers SHOULD interpret a path name component ".." as referring to
+   the parent directory, and "." as referring to the current directory.
+   If the server implementation limits access to certain parts of the
+   file system, it must be extra careful in parsing file names when
+   enforcing such restrictions.  There have been numerous reported
+   security bugs where a ".." in a path name has allowed access outside
+   the intended area.
+
+   An empty path name is valid, and it refers to the user's default
+   directory (usually the user's home directory).
+
+   Otherwise, no syntax is defined for file names by this specification.
+   Clients should not make any other assumptions; however, they can
+   splice path name components returned by SSH_FXP_READDIR together
+   using a slash ('/') as the separator, and that will work as expected.
+
+   It is understood that the lack of well-defined semantics for file
+   names may cause interoperability problems between clients and servers
+   using radically different operating systems.  However, this approach
+   is known to work acceptably with most systems, and alternative
+   approaches that e.g.  treat file names as sequences of structured
+   components are quite complicated.
+
+6.3 Opening, Creating, and Closing Files
+
+    Files are opened and created using the SSH_FXP_OPEN message, whose
+   data part is as follows:
+
+   	uint32        id
+   	string        filename
+   	uint32        pflags
+   	ATTRS         attrs
+
+   The `id' field is the request identifier as for all requests.
+
+   The `filename' field specifies the file name.  See Section ``File
+   Names'' for more information.
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 11]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+    The `pflags' field is a bitmask.  The following bits have been
+   defined.
+
+   	#define SSH_FXF_READ            0x00000001
+   	#define SSH_FXF_WRITE           0x00000002
+   	#define SSH_FXF_APPEND          0x00000004
+   	#define SSH_FXF_CREAT           0x00000008
+   	#define SSH_FXF_TRUNC           0x00000010
+   	#define SSH_FXF_EXCL            0x00000020
+
+   These have the following meanings:
+
+   SSH_FXF_READ
+      Open the file for reading.
+
+   SSH_FXF_WRITE
+      Open the file for writing.  If both this and SSH_FXF_READ are
+      specified, the file is opened for both reading and writing.
+
+   SSH_FXF_APPEND
+      Force all writes to append data at the end of the file.
+
+   SSH_FXF_CREAT
+      If this flag is specified, then a new file will be created if one
+      does not already exist (if O_TRUNC is specified, the new file will
+      be truncated to zero length if it previously exists).
+
+   SSH_FXF_TRUNC
+      Forces an existing file with the same name to be truncated to zero
+      length when creating a file by specifying SSH_FXF_CREAT.
+      SSH_FXF_CREAT MUST also be specified if this flag is used.
+
+   SSH_FXF_EXCL
+      Causes the request to fail if the named file already exists.
+      SSH_FXF_CREAT MUST also be specified if this flag is used.
+
+   The `attrs' field specifies the initial attributes for the file.
+   Default values will be used for those attributes that are not
+   specified.  See Section ``File Attributes'' for more information.
+
+   Regardless the server operating system, the file will always be
+   opened in "binary" mode (i.e., no translations between different
+   character sets and newline encodings).
+
+   The response to this message will be either SSH_FXP_HANDLE (if the
+   operation is successful) or SSH_FXP_STATUS (if the operation fails).
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 12]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+    A file is closed by using the SSH_FXP_CLOSE request.  Its data field
+   has the following format:
+
+   	uint32     id
+   	string     handle
+
+   where `id' is the request identifier, and `handle' is a handle
+   previously returned in the response to SSH_FXP_OPEN or
+   SSH_FXP_OPENDIR.  The handle becomes invalid immediately after this
+   request has been sent.
+
+   The response to this request will be a SSH_FXP_STATUS message.  One
+   should note that on some server platforms even a close can fail.
+   This can happen e.g.  if the server operating system caches writes,
+   and an error occurs while flushing cached writes during the close.
+
+6.4 Reading and Writing
+
+    Once a file has been opened, it can be read using the SSH_FXP_READ
+   message, which has the following format:
+
+   	uint32     id
+   	string     handle
+   	uint64     offset
+   	uint32     len
+
+   where `id' is the request identifier, `handle' is an open file handle
+   returned by SSH_FXP_OPEN, `offset' is the offset (in bytes) relative
+   to the beginning of the file from where to start reading, and `len'
+   is the maximum number of bytes to read.
+
+   In response to this request, the server will read as many bytes as it
+   can from the file (up to `len'), and return them in a SSH_FXP_DATA
+   message.  If an error occurs or EOF is encountered before reading any
+   data, the server will respond with SSH_FXP_STATUS.  For normal disk
+   files, it is guaranteed that this will read the specified number of
+   bytes, or up to end of file.  For e.g.  device files this may return
+   fewer bytes than requested.
+
+    Writing to a file is achieved using the SSH_FXP_WRITE message, which
+   has the following format:
+
+   	uint32     id
+   	string     handle
+   	uint64     offset
+   	string     data
+
+   where `id' is a request identifier, `handle' is a file handle
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 13]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+   returned by SSH_FXP_OPEN, `offset' is the offset (in bytes) from the
+   beginning of the file where to start writing, and `data' is the data
+   to be written.
+
+   The write will extend the file if writing beyond the end of the file.
+   It is legal to write way beyond the end of the file; the semantics
+   are to write zeroes from the end of the file to the specified offset
+   and then the data.  On most operating systems, such writes do not
+   allocate disk space but instead leave "holes" in the file.
+
+   The server responds to a write request with a SSH_FXP_STATUS message.
+
+6.5 Removing and Renaming Files
+
+    Files can be removed using the SSH_FXP_REMOVE message.  It has the
+   following format:
+
+   	uint32     id
+   	string     filename
+
+   where `id' is the request identifier and `filename' is the name of
+   the file to be removed.  See Section ``File Names'' for more
+   information.  This request cannot be used to remove directories.
+
+   The server will respond to this request with a SSH_FXP_STATUS
+   message.
+
+    Files (and directories) can be renamed using the SSH_FXP_RENAME
+   message.  Its data is as follows:
+
+   	uint32     id
+   	string     oldpath
+   	string     newpath
+
+   where `id' is the request identifier, `oldpath' is the name of an
+   existing file or directory, and `newpath' is the new name for the
+   file or directory.  It is an error if there already exists a file
+   with the name specified by newpath.  The server may also fail rename
+   requests in other situations, for example if `oldpath' and `newpath'
+   point to different file systems on the server.
+
+   The server will respond to this request with a SSH_FXP_STATUS
+   message.
+
+
+
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 14]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+6.6 Creating and Deleting Directories
+
+    New directories can be created using the SSH_FXP_MKDIR request.  It
+   has the following format:
+
+   	uint32     id
+   	string     path
+   	ATTRS      attrs
+
+   where `id' is the request identifier, `path' and `attrs' specifies
+   the modifications to be made to its attributes.  See Section ``File
+   Names'' for more information on file names.  Attributes are discussed
+   in more detail in Section ``File Attributes''.  specifies the
+   directory to be created.  An error will be returned if a file or
+   directory with the specified path already exists.  The server will
+   respond to this request with a SSH_FXP_STATUS message.
+
+    Directories can be removed using the SSH_FXP_RMDIR request, which
+   has the following format:
+
+   	uint32     id
+   	string     path
+
+   where `id' is the request identifier, and `path' specifies the
+   directory to be removed.  See Section ``File Names'' for more
+   information on file names.  An error will be returned if no directory
+   with the specified path exists, or if the specified directory is not
+   empty, or if the path specified a file system object other than a
+   directory.  The server responds to this request with a SSH_FXP_STATUS
+   message.
+
+6.7 Scanning Directories
+
+   The files in a directory can be listed using the SSH_FXP_OPENDIR and
+   SSH_FXP_READDIR requests.  Each SSH_FXP_READDIR request returns one
+   or more file names with full file attributes for each file.  The
+   client should call SSH_FXP_READDIR repeatedly until it has found the
+   file it is looking for or until the server responds with a
+   SSH_FXP_STATUS message indicating an error (normally SSH_FX_EOF if
+   there are no more files in the directory).  The client should then
+   close the handle using the SSH_FXP_CLOSE request.
+
+
+
+
+
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 15]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+    The SSH_FXP_OPENDIR opens a directory for reading.  It has the
+   following format:
+
+   	uint32     id
+   	string     path
+
+   where `id' is the request identifier and `path' is the path name of
+   the directory to be listed (without any trailing slash).  See Section
+   ``File Names'' for more information on file names.  This will return
+   an error if the path does not specify a directory or if the directory
+   is not readable.  The server will respond to this request with either
+   a SSH_FXP_HANDLE or a SSH_FXP_STATUS message.
+
+    Once the directory has been successfully opened, files (and
+   directories) contained in it can be listed using SSH_FXP_READDIR
+   requests.  These are of the format
+
+   	uint32     id
+   	string     handle
+
+   where `id' is the request identifier, and `handle' is a handle
+   returned by SSH_FXP_OPENDIR.  (It is a protocol error to attempt to
+   use an ordinary file handle returned by SSH_FXP_OPEN.)
+
+   The server responds to this request with either a SSH_FXP_NAME or a
+   SSH_FXP_STATUS message.  One or more names may be returned at a time.
+   Full status information is returned for each name in order to speed
+   up typical directory listings.
+
+   When the client no longer wishes to read more names from the
+   directory, it SHOULD call SSH_FXP_CLOSE for the handle.  The handle
+   should be closed regardless of whether an error has occurred or not.
+
+6.8 Retrieving File Attributes
+
+   Very often, file attributes are automatically returned by
+   SSH_FXP_READDIR.  However, sometimes there is need to specifically
+   retrieve the attributes for a named file.  This can be done using the
+   SSH_FXP_STAT, SSH_FXP_LSTAT and SSH_FXP_FSTAT requests.
+
+    SSH_FXP_STAT and SSH_FXP_LSTAT only differ in that SSH_FXP_STAT
+   follows symbolic links on the server, whereas SSH_FXP_LSTAT does not
+   follow symbolic links.  Both have the same format:
+
+   	uint32     id
+   	string     path
+
+   where `id' is the request identifier, and `path' specifies the file
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 16]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+   system object for which status is to be returned.  The server
+   responds to this request with either SSH_FXP_ATTRS or SSH_FXP_STATUS.
+
+    SSH_FXP_FSTAT differs from the others in that it returns status
+   information for an open file (identified by the file handle).  Its
+   format is as follows:
+
+   	uint32     id
+   	string     handle
+
+   where `id' is the request identifier and `handle' is a file handle
+   returned by SSH_FXP_OPEN.  The server responds to this request with
+   SSH_FXP_ATTRS or SSH_FXP_STATUS.
+
+6.9 Setting File Attributes
+
+   File attributes may be modified using the SSH_FXP_SETSTAT and
+   SSH_FXP_FSETSTAT requests.  These requests are used for operations
+   such as changing the ownership, permissions or access times, as well
+   as for truncating a file.
+
+    The SSH_FXP_SETSTAT request is of the following format:
+
+   	uint32     id
+   	string     path
+   	ATTRS      attrs
+
+   where `id' is the request identifier, `path' specifies the file
+   system object (e.g.  file or directory) whose attributes are to be
+   modified, and `attrs' specifies the modifications to be made to its
+   attributes.  Attributes are discussed in more detail in Section
+   ``File Attributes''.
+
+   An error will be returned if the specified file system object does
+   not exist or the user does not have sufficient rights to modify the
+   specified attributes.  The server responds to this request with a
+   SSH_FXP_STATUS message.
+
+    The SSH_FXP_FSETSTAT request modifies the attributes of a file which
+   is already open.  It has the following format:
+
+   	uint32     id
+   	string     handle
+   	ATTRS      attrs
+
+   where `id' is the request identifier, `handle' (MUST be returned by
+   SSH_FXP_OPEN) identifies the file whose attributes are to be
+   modified, and `attrs' specifies the modifications to be made to its
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 17]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+   attributes.  Attributes are discussed in more detail in Section
+   ``File Attributes''.  The server will respond to this request with
+   SSH_FXP_STATUS.
+
+6.10 Dealing with Symbolic links
+
+    The SSH_FXP_READLINK request may be used to read the target of a
+   symbolic link.  It would have a data part as follows:
+
+   	uint32     id
+   	string     path
+
+   where `id' is the request identifier and `path' specifies the path
+   name of the symlink to be read.
+
+   The server will respond with a SSH_FXP_NAME packet containing only
+   one name and a dummy attributes value.  The name in the returned
+   packet contains the target of the link.  If an error occurs, the
+   server may respond with SSH_FXP_STATUS.
+
+    The SSH_FXP_SYMLINK request will create a symbolic link on the
+   server.  It is of the following format
+
+   	uint32     id
+   	string     linkpath
+   	string     targetpath
+
+   where `id' is the request identifier, `linkpath' specifies the path
+   name of the symlink to be created and `targetpath' specifies the
+   target of the symlink.  The server shall respond with a
+   SSH_FXP_STATUS indicating either success (SSH_FX_OK) or an error
+   condition.
+
+6.11 Canonicalizing the Server-Side Path Name
+
+    The SSH_FXP_REALPATH request can be used to have the server
+   canonicalize any given path name to an absolute path.  This is useful
+   for converting path names containing ".." components or relative
+   pathnames without a leading slash into absolute paths.  The format of
+   the request is as follows:
+
+   	uint32     id
+   	string     path
+
+   where `id' is the request identifier and `path' specifies the path
+   name to be canonicalized.  The server will respond with a
+   SSH_FXP_NAME packet containing only one name and a dummy attributes
+   value.  The name is the returned packet will be in canonical form.
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 18]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+   If an error occurs, the server may also respond with SSH_FXP_STATUS.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 19]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+7. Responses from the Server to the Client
+
+   The server responds to the client using one of a few response
+   packets.  All requests can return a SSH_FXP_STATUS response upon
+   failure.  When the operation is successful, any of the responses may
+   be returned (depending on the operation).  If no data needs to be
+   returned to the client, the SSH_FXP_STATUS response with SSH_FX_OK
+   status is appropriate.  Otherwise, the SSH_FXP_HANDLE message is used
+   to return a file handle (for SSH_FXP_OPEN and SSH_FXP_OPENDIR
+   requests), SSH_FXP_DATA is used to return data from SSH_FXP_READ,
+   SSH_FXP_NAME is used to return one or more file names from a
+   SSH_FXP_READDIR or SSH_FXP_REALPATH request, and SSH_FXP_ATTRS is
+   used to return file attributes from SSH_FXP_STAT, SSH_FXP_LSTAT, and
+   SSH_FXP_FSTAT requests.
+
+   Exactly one response will be returned for each request.  Each
+   response packet contains a request identifier which can be used to
+   match each response with the corresponding request.  Note that it is
+   legal to have several requests outstanding simultaneously, and the
+   server is allowed to send responses to them in a different order from
+   the order in which the requests were sent (the result of their
+   execution, however, is guaranteed to be as if they had been processed
+   one at a time in the order in which the requests were sent).
+
+   Response packets are of the same general format as request packets.
+   Each response packet begins with the request identifier.
+
+    The format of the data portion of the SSH_FXP_STATUS response is as
+   follows:
+
+   	uint32     id
+   	uint32     error/status code
+   	string     error message (ISO-10646 UTF-8 [RFC-2279])
+   	string     language tag (as defined in [RFC-1766])
+
+   where `id' is the request identifier, and `error/status code'
+   indicates the result of the requested operation.  The value SSH_FX_OK
+   indicates success, and all other values indicate failure.
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 20]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+    Currently, the following values are defined (other values may be
+   defined by future versions of this protocol):
+
+   	#define SSH_FX_OK                            0
+   	#define SSH_FX_EOF                           1
+   	#define SSH_FX_NO_SUCH_FILE                  2
+   	#define SSH_FX_PERMISSION_DENIED             3
+   	#define SSH_FX_FAILURE                       4
+   	#define SSH_FX_BAD_MESSAGE                   5
+   	#define SSH_FX_NO_CONNECTION                 6
+   	#define SSH_FX_CONNECTION_LOST               7
+   	#define SSH_FX_OP_UNSUPPORTED                8
+
+   SSH_FX_OK
+      Indicates successful completion of the operation.
+
+   SSH_FX_EOF
+      indicates end-of-file condition; for SSH_FX_READ it means that no
+      more data is available in the file, and for SSH_FX_READDIR it
+      indicates that no more files are contained in the directory.
+
+   SSH_FX_NO_SUCH_FILE
+      is returned when a reference is made to a file which should exist
+      but doesn't.
+
+   SSH_FX_PERMISSION_DENIED
+      is returned when the authenticated user does not have sufficient
+      permissions to perform the operation.
+
+   SSH_FX_FAILURE
+      is a generic catch-all error message; it should be returned if an
+      error occurs for which there is no more specific error code
+      defined.
+
+   SSH_FX_BAD_MESSAGE
+      may be returned if a badly formatted packet or protocol
+      incompatibility is detected.
+
+   SSH_FX_NO_CONNECTION
+      is a pseudo-error which indicates that the client has no
+      connection to the server (it can only be generated locally by the
+      client, and MUST NOT be returned by servers).
+
+   SSH_FX_CONNECTION_LOST
+      is a pseudo-error which indicates that the connection to the
+      server has been lost (it can only be generated locally by the
+      client, and MUST NOT be returned by servers).
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 21]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+   SSH_FX_OP_UNSUPPORTED
+      indicates that an attempt was made to perform an operation which
+      is not supported for the server (it may be generated locally by
+      the client if e.g.  the version number exchange indicates that a
+      required feature is not supported by the server, or it may be
+      returned by the server if the server does not implement an
+      operation).
+
+   The SSH_FXP_HANDLE response has the following format:
+
+   	uint32     id
+   	string     handle
+
+   where `id' is the request identifier, and `handle' is an arbitrary
+   string that identifies an open file or directory on the server.  The
+   handle is opaque to the client; the client MUST NOT attempt to
+   interpret or modify it in any way.  The length of the handle string
+   MUST NOT exceed 256 data bytes.
+
+    The SSH_FXP_DATA response has the following format:
+
+   	uint32     id
+   	string     data
+
+   where `id' is the request identifier, and `data' is an arbitrary byte
+   string containing the requested data.  The data string may be at most
+   the number of bytes requested in a SSH_FXP_READ request, but may also
+   be shorter if end of file is reached or if the read is from something
+   other than a regular file.
+
+    The SSH_FXP_NAME response has the following format:
+
+   	uint32     id
+   	uint32     count
+   	repeats count times:
+   		string     filename
+   		string     longname
+   		ATTRS      attrs
+
+   where `id' is the request identifier, `count' is the number of names
+   returned in this response, and the remaining fields repeat `count'
+   times (so that all three fields are first included for the first
+   file, then for the second file, etc).  In the repeated part,
+   `filename' is a file name being returned (for SSH_FXP_READDIR, it
+   will be a relative name within the directory, without any path
+   components; for SSH_FXP_REALPATH it will be an absolute path name),
+   `longname' is an expanded format for the file name, similar to what
+   is returned by "ls -l" on Unix systems, and `attrs' is the attributes
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 22]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+   of the file as described in Section ``File Attributes''.
+
+   The format of the `longname' field is unspecified by this protocol.
+   It MUST be suitable for use in the output of a directory listing
+   command (in fact, the recommended operation for a directory listing
+   command is to simply display this data).  However, clients SHOULD NOT
+   attempt to parse the longname field for file attributes; they SHOULD
+   use the attrs field instead.
+
+    The recommended format for the longname field is as follows:
+
+   	-rwxr-xr-x   1 mjos     staff      348911 Mar 25 14:29 t-filexfer
+   	1234567890 123 12345678 12345678 12345678 123456789012
+
+   Here, the first line is sample output, and the second field indicates
+   widths of the various fields.  Fields are separated by spaces.  The
+   first field lists file permissions for user, group, and others; the
+   second field is link count; the third field is the name of the user
+   who owns the file; the fourth field is the name of the group that
+   owns the file; the fifth field is the size of the file in bytes; the
+   sixth field (which actually may contain spaces, but is fixed to 12
+   characters) is the file modification time, and the seventh field is
+   the file name.  Each field is specified to be a minimum of certain
+   number of character positions (indicated by the second line above),
+   but may also be longer if the data does not fit in the specified
+   length.
+
+    The SSH_FXP_ATTRS response has the following format:
+
+   	uint32     id
+   	ATTRS      attrs
+
+   where `id' is the request identifier, and `attrs' is the returned
+   file attributes as described in Section ``File Attributes''.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 23]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+8. Vendor-Specific Extensions
+
+    The SSH_FXP_EXTENDED request provides a generic extension mechanism
+   for adding vendor-specific commands.  The request has the following
+   format:
+
+   	uint32     id
+   	string     extended-request
+   	... any request-specific data ...
+
+   where `id' is the request identifier, and `extended-request' is a
+   string of the format "name@domain", where domain is an internet
+   domain name of the vendor defining the request.  The rest of the
+   request is completely vendor-specific, and servers should only
+   attempt to interpret it if they recognize the `extended-request'
+   name.
+
+   The server may respond to such requests using any of the response
+   packets defined in Section ``Responses from the Server to the
+   Client''.  Additionally, the server may also respond with a
+   SSH_FXP_EXTENDED_REPLY packet, as defined below.  If the server does
+   not recognize the `extended-request' name, then the server MUST
+   respond with SSH_FXP_STATUS with error/status set to
+   SSH_FX_OP_UNSUPPORTED.
+
+    The SSH_FXP_EXTENDED_REPLY packet can be used to carry arbitrary
+   extension-specific data from the server to the client.  It is of the
+   following format:
+
+   	uint32     id
+   	... any request-specific data ...
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 24]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+9. Security Considerations
+
+   This protocol assumes that it is run over a secure channel and that
+   the endpoints of the channel have been authenticated.  Thus, this
+   protocol assumes that it is externally protected from network-level
+   attacks.
+
+   This protocol provides file system access to arbitrary files on the
+   server (only constrained by the server implementation).  It is the
+   responsibility of the server implementation to enforce any access
+   controls that may be required to limit the access allowed for any
+   particular user (the user being authenticated externally to this
+   protocol, typically using the SSH User Authentication Protocol [6].
+
+   Care must be taken in the server implementation to check the validity
+   of received file handle strings.  The server should not rely on them
+   directly; it MUST check the validity of each handle before relying on
+   it.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 25]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+10. Changes from previous protocol versions
+
+   The SSH File Transfer Protocol has changed over time, before it's
+   standardization.  The following is a description of the incompatible
+   changes between different versions.
+
+10.1 Changes between versions 3 and 2
+
+   o  The SSH_FXP_READLINK and SSH_FXP_SYMLINK messages were added.
+
+   o  The SSH_FXP_EXTENDED and SSH_FXP_EXTENDED_REPLY messages were
+      added.
+
+   o  The SSH_FXP_STATUS message was changed to include fields `error
+      message' and `language tag'.
+
+
+10.2 Changes between versions 2 and 1
+
+   o  The SSH_FXP_RENAME message was added.
+
+
+10.3 Changes between versions 1 and 0
+
+   o  Implementation changes, no actual protocol changes.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 26]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+11. Trademark Issues
+
+   "ssh" is a registered trademark of SSH Communications Security Corp
+   in the United States and/or other countries.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 27]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+References
+
+   [1]  Dierks, T., Allen, C., Treese, W., Karlton, P., Freier, A. and
+        P. Kocher, "The TLS Protocol Version 1.0", RFC 2246, January
+        1999.
+
+   [2]  Institute of Electrical and Electronics Engineers, "Information
+        Technology - Portable Operating System Interface (POSIX) - Part
+        1: System Application Program Interface (API) [C Language]",
+        IEEE Standard 1003.2, 1996.
+
+   [3]  Rinne, T., Ylonen, T., Kivinen, T., Saarinen, M. and S.
+        Lehtinen, "SSH Protocol Architecture", draft-ietf-secsh-
+        architecture-09 (work in progress), July 2001.
+
+   [4]  Rinne, T., Ylonen, T., Kivinen, T., Saarinen, M. and S.
+        Lehtinen, "SSH Protocol Transport Protocol", draft-ietf-secsh-
+        architecture-09 (work in progress), July 2001.
+
+   [5]  Rinne, T., Ylonen, T., Kivinen, T., Saarinen, M. and S.
+        Lehtinen, "SSH Connection Protocol", draft-ietf-secsh-connect-11
+        (work in progress), July 2001.
+
+   [6]  Rinne, T., Ylonen, T., Kivinen, T., Saarinen, M. and S.
+        Lehtinen, "SSH Authentication Protocol", draft-ietf-secsh-
+        userauth-11 (work in progress), July 2001.
+
+
+Authors' Addresses
+
+   Tatu Ylonen
+   SSH Communications Security Corp
+   Fredrikinkatu 42
+   HELSINKI  FIN-00100
+   Finland
+
+   EMail: [email protected]
+
+
+   Sami Lehtinen
+   SSH Communications Security Corp
+   Fredrikinkatu 42
+   HELSINKI  FIN-00100
+   Finland
+
+   EMail: [email protected]
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 28]
+
+Internet-Draft         SSH File Transfer Protocol           October 2001
+
+
+Full Copyright Statement
+
+   Copyright (C) The Internet Society (2001).  All Rights Reserved.
+
+   This document and translations of it may be copied and furnished to
+   others, and derivative works that comment on or otherwise explain it
+   or assist in its implementation may be prepared, copied, published
+   and distributed, in whole or in part, without restriction of any
+   kind, provided that the above copyright notice and this paragraph are
+   included on all such copies and derivative works.  However, this
+   document itself may not be modified in any way, such as by removing
+   the copyright notice or references to the Internet Society or other
+   Internet organizations, except as needed for the purpose of
+   developing Internet standards in which case the procedures for
+   copyrights defined in the Internet Standards process must be
+   followed, or as required to translate it into languages other than
+   English.
+
+   The limited permissions granted above are perpetual and will not be
+   revoked by the Internet Society or its successors or assigns.
+
+   This document and the information contained herein is provided on an
+   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
+   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
+   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
+   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
+   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+
+Acknowledgement
+
+   Funding for the RFC Editor function is currently provided by the
+   Internet Society.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Lehtinen         Expires April 1, 2002                [Page 29]
+
+
+
diff --git a/lib/ssh/doc/standard/draft-ietf-secsh-filexfer-03.2.ps b/lib/ssh/doc/standard/draft-ietf-secsh-filexfer-03.2.ps
new file mode 100644
index 0000000000..6a40cd6067
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+5 701 M
+(Secure Shell Working Group                                  J. Galbraith) s
+5 690 M
+(Internet-Draft                                          VanDyke Software) s
+5 679 M
+(Expires: April 16, 2003                                        T. Ylonen) s
+5 668 M
+(                                                             S. Lehtinen) s
+5 657 M
+(                                        SSH Communications Security Corp) s
+5 646 M
+(                                                        October 16, 2002) s
+5 613 M
+(                       SSH File Transfer Protocol) s
+5 602 M
+(                    draft-ietf-secsh-filexfer-03.txt) s
+5 580 M
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+5 558 M
+(   This document is an Internet-Draft and is in full conformance with) s
+5 547 M
+(   all provisions of Section 10 of RFC2026.) s
+5 525 M
+(   Internet-Drafts are working documents of the Internet Engineering) s
+5 514 M
+(   Task Force \(IETF\), its areas, and its working groups.  Note that) s
+5 503 M
+(   other groups may also distribute working documents as Internet-) s
+5 492 M
+(   Drafts.) s
+5 470 M
+(   Internet-Drafts are draft documents valid for a maximum of six months) s
+5 459 M
+(   and may be updated, replaced, or obsoleted by other documents at any) s
+5 448 M
+(   time.  It is inappropriate to use Internet-Drafts as reference) s
+5 437 M
+(   material or to cite them other than as "work in progress.") s
+5 415 M
+(   The list of current Internet-Drafts can be accessed at http://) s
+5 404 M
+(   www.ietf.org/ietf/1id-abstracts.txt.) s
+5 382 M
+(   The list of Internet-Draft Shadow Directories can be accessed at) s
+5 371 M
+(   http://www.ietf.org/shadow.html.) s
+5 349 M
+(   This Internet-Draft will expire on April 16, 2003.) s
+5 327 M
+(Copyright Notice) s
+5 305 M
+(   Copyright \(C\) The Internet Society \(2002\).  All Rights Reserved.) s
+5 283 M
+(Abstract) s
+5 261 M
+(   The SSH File Transfer Protocol provides secure file transfer) s
+5 250 M
+(   functionality over any reliable data stream.  It is the standard file) s
+5 239 M
+(   transfer protocol for use with the SSH2 protocol.  This document) s
+5 228 M
+(   describes the file transfer protocol and its interface to the SSH2) s
+5 217 M
+(   protocol suite.) s
+5 129 M
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+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 2 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
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+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(Table of Contents) s
+5 668 M
+(   1.     Introduction . . . . . . . . . . . . . . . . . . . . . . .   3) s
+5 657 M
+(   2.     Use with the SSH Connection Protocol . . . . . . . . . . .   4) s
+5 646 M
+(   3.     General Packet Format  . . . . . . . . . . . . . . . . . .   5) s
+5 635 M
+(   4.     Protocol Initialization  . . . . . . . . . . . . . . . . .   7) s
+5 624 M
+(   4.1    Client Initialization  . . . . . . . . . . . . . . . . . .   7) s
+5 613 M
+(   4.2    Server Initialization  . . . . . . . . . . . . . . . . . .   7) s
+5 602 M
+(   4.3    Determining Server Newline Convention  . . . . . . . . . .   8) s
+5 591 M
+(   5.     File Attributes  . . . . . . . . . . . . . . . . . . . . .   9) s
+5 580 M
+(   5.1    Flags  . . . . . . . . . . . . . . . . . . . . . . . . . .   9) s
+5 569 M
+(   5.2    Type . . . . . . . . . . . . . . . . . . . . . . . . . . .  10) s
+5 558 M
+(   5.3    Size . . . . . . . . . . . . . . . . . . . . . . . . . . .  10) s
+5 547 M
+(   5.4    Owner and Group  . . . . . . . . . . . . . . . . . . . . .  10) s
+5 536 M
+(   5.5    Permissions  . . . . . . . . . . . . . . . . . . . . . . .  11) s
+5 525 M
+(   5.6    Times  . . . . . . . . . . . . . . . . . . . . . . . . . .  11) s
+5 514 M
+(   5.7    ACL  . . . . . . . . . . . . . . . . . . . . . . . . . . .  11) s
+5 503 M
+(   5.8    Extended attributes  . . . . . . . . . . . . . . . . . . .  12) s
+5 492 M
+(   6.     Requests From the Client to the Server . . . . . . . . . .  13) s
+5 481 M
+(   6.1    Request Synchronization and Reordering . . . . . . . . . .  13) s
+5 470 M
+(   6.2    File Names . . . . . . . . . . . . . . . . . . . . . . . .  14) s
+5 459 M
+(   6.3    Opening, Creating, and Closing Files . . . . . . . . . . .  14) s
+5 448 M
+(   6.4    Reading and Writing  . . . . . . . . . . . . . . . . . . .  17) s
+5 437 M
+(   6.5    Removing and Renaming Files  . . . . . . . . . . . . . . .  18) s
+5 426 M
+(   6.6    Creating and Deleting Directories  . . . . . . . . . . . .  19) s
+5 415 M
+(   6.7    Scanning Directories . . . . . . . . . . . . . . . . . . .  19) s
+5 404 M
+(   6.8    Retrieving File Attributes . . . . . . . . . . . . . . . .  20) s
+5 393 M
+(   6.9    Setting File Attributes  . . . . . . . . . . . . . . . . .  21) s
+5 382 M
+(   6.10   Dealing with Symbolic links  . . . . . . . . . . . . . . .  22) s
+5 371 M
+(   6.11   Canonicalizing the Server-Side Path Name . . . . . . . . .  23) s
+5 360 M
+(   6.11.1 Best practice for dealing with paths . . . . . . . . . . .  23) s
+5 349 M
+(   7.     Responses from the Server to the Client  . . . . . . . . .  24) s
+5 338 M
+(   8.     Vendor-Specific Extensions . . . . . . . . . . . . . . . .  28) s
+5 327 M
+(   9.     Security Considerations  . . . . . . . . . . . . . . . . .  29) s
+5 316 M
+(   10.    Changes from previous protocol versions  . . . . . . . . .  30) s
+5 305 M
+(   10.1   Changes between versions 4 and 3 . . . . . . . . . . . . .  30) s
+5 294 M
+(   10.2   Changes between versions 3 and 2 . . . . . . . . . . . . .  31) s
+5 283 M
+(   10.3   Changes between versions 2 and 1 . . . . . . . . . . . . .  31) s
+5 272 M
+(   10.4   Changes between versions 1 and 0 . . . . . . . . . . . . .  31) s
+5 261 M
+(   11.    Trademark Issues . . . . . . . . . . . . . . . . . . . . .  32) s
+5 250 M
+(          References . . . . . . . . . . . . . . . . . . . . . . . .  33) s
+5 239 M
+(          Authors' Addresses . . . . . . . . . . . . . . . . . . . .  33) s
+5 228 M
+(          Full Copyright Statement . . . . . . . . . . . . . . . . .  35) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                 [Page 2]) s
+_R
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+PStoPSxform concat
+%%BeginPageSetup
+_S
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+/pagenum 3 def
+/fname () def
+/fdir () def
+/ftail () def
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+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(1. Introduction) s
+5 668 M
+(   This protocol provides secure file transfer \(and more generally file) s
+5 657 M
+(   system access\) functionality over a reliable data stream, such as a) s
+5 646 M
+(   channel in the SSH2 protocol [5].) s
+5 624 M
+(   This protocol is designed so that it could be used to implement a) s
+5 613 M
+(   secure remote file system service, as well as a secure file transfer) s
+5 602 M
+(   service.) s
+5 580 M
+(   This protocol assumes that it runs over a secure channel, and that) s
+5 569 M
+(   the server has already authenticated the user at the client end, and) s
+5 558 M
+(   that the identity of the client user is externally available to the) s
+5 547 M
+(   server implementation.) s
+5 525 M
+(   In general, this protocol follows a simple request-response model.) s
+5 514 M
+(   Each request and response contains a sequence number and multiple) s
+5 503 M
+(   requests may be pending simultaneously.  There are a relatively large) s
+5 492 M
+(   number of different request messages, but a small number of possible) s
+5 481 M
+(   response messages.  Each request has one or more response messages) s
+5 470 M
+(   that may be returned in result \(e.g., a read either returns data or) s
+5 459 M
+(   reports error status\).) s
+5 437 M
+(   The packet format descriptions in this specification follow the) s
+5 426 M
+(   notation presented in the secsh architecture draft. [5]) s
+5 404 M
+(   Even though this protocol is described in the context of the SSH2) s
+5 393 M
+(   protocol, this protocol is general and independent of the rest of the) s
+5 382 M
+(   SSH2 protocol suite.  It could be used in a number of different) s
+5 371 M
+(   applications, such as secure file transfer over TLS RFC 2246 [1] and) s
+5 360 M
+(   transfer of management information in VPN applications.) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                 [Page 3]) s
+_R
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+/pagenum 4 def
+/fname () def
+/fdir () def
+/ftail () def
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+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(2. Use with the SSH Connection Protocol) s
+5 668 M
+(   When used with the SSH2 Protocol suite, this protocol is intended to) s
+5 657 M
+(   be used from the SSH Connection Protocol [7] as a subsystem, as) s
+5 646 M
+(   described in section ``Starting a Shell or a Command''.  The) s
+5 635 M
+(   subsystem name used with this protocol is "sftp".) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                 [Page 4]) s
+_R
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+%%BeginPageSetup
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+/pagenum 5 def
+/fname () def
+/fdir () def
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+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(3. General Packet Format) s
+5 668 M
+(   All packets transmitted over the secure connection are of the) s
+5 657 M
+(   following format:) s
+5 635 M
+(        uint32             length) s
+5 624 M
+(        byte               type) s
+5 613 M
+(        byte[length - 1]   data payload) s
+5 591 M
+(   That is, they are just data preceded by 32-bit length and 8-bit type) s
+5 580 M
+(   fields.  The `length' is the length of the data area, and does not) s
+5 569 M
+(   include the `length' field itself.  The format and interpretation of) s
+5 558 M
+(   the data area depends on the packet type.) s
+5 536 M
+(   All packet descriptions below only specify the packet type and the) s
+5 525 M
+(   data that goes into the data field.  Thus, they should be prefixed by) s
+5 514 M
+(   the `length' and `type' fields.) s
+5 492 M
+(   The maximum size of a packet is in practice determined by the client) s
+5 481 M
+(   \(the maximum size of read or write requests that it sends, plus a few) s
+5 470 M
+(   bytes of packet overhead\).  All servers SHOULD support packets of at) s
+5 459 M
+(   least 34000 bytes \(where the packet size refers to the full length,) s
+5 448 M
+(   including the header above\).  This should allow for reads and writes) s
+5 437 M
+(   of at most 32768 bytes.) s
+5 415 M
+(   There is no limit on the number of outstanding \(non-acknowledged\)) s
+5 404 M
+(   requests that the client may send to the server.  In practice this is) s
+5 393 M
+(   limited by the buffering available on the data stream and the queuing) s
+5 382 M
+(   performed by the server.  If the server's queues are full, it should) s
+5 371 M
+(   not read any more data from the stream, and flow control will prevent) s
+5 360 M
+(   the client from sending more requests.  Note, however, that while) s
+5 349 M
+(   there is no restriction on the protocol level, the client's API may) s
+5 338 M
+(   provide a limit in order to prevent infinite queuing of outgoing) s
+5 327 M
+(   requests at the client.) s
+5 305 M
+(   The following values are defined for packet types.) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                 [Page 5]) s
+_R
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+595.000000 421.271378 translate
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+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 6 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
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+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(        #define SSH_FXP_INIT                1) s
+5 679 M
+(        #define SSH_FXP_VERSION             2) s
+5 668 M
+(        #define SSH_FXP_OPEN                3) s
+5 657 M
+(        #define SSH_FXP_CLOSE               4) s
+5 646 M
+(        #define SSH_FXP_READ                5) s
+5 635 M
+(        #define SSH_FXP_WRITE               6) s
+5 624 M
+(        #define SSH_FXP_LSTAT               7) s
+5 613 M
+(        #define SSH_FXP_FSTAT               8) s
+5 602 M
+(        #define SSH_FXP_SETSTAT             9) s
+5 591 M
+(        #define SSH_FXP_FSETSTAT           10) s
+5 580 M
+(        #define SSH_FXP_OPENDIR            11) s
+5 569 M
+(        #define SSH_FXP_READDIR            12) s
+5 558 M
+(        #define SSH_FXP_REMOVE             13) s
+5 547 M
+(        #define SSH_FXP_MKDIR              14) s
+5 536 M
+(        #define SSH_FXP_RMDIR              15) s
+5 525 M
+(        #define SSH_FXP_REALPATH           16) s
+5 514 M
+(        #define SSH_FXP_STAT               17) s
+5 503 M
+(        #define SSH_FXP_RENAME             18) s
+5 492 M
+(        #define SSH_FXP_READLINK           19) s
+5 481 M
+(        #define SSH_FXP_SYMLINK            20) s
+5 459 M
+(        #define SSH_FXP_STATUS            101) s
+5 448 M
+(        #define SSH_FXP_HANDLE            102) s
+5 437 M
+(        #define SSH_FXP_DATA              103) s
+5 426 M
+(        #define SSH_FXP_NAME              104) s
+5 415 M
+(        #define SSH_FXP_ATTRS             105) s
+5 393 M
+(        #define SSH_FXP_EXTENDED          200) s
+5 382 M
+(        #define SSH_FXP_EXTENDED_REPLY    201) s
+5 360 M
+(        RESERVED_FOR_EXTENSIONS            210-255) s
+5 338 M
+(   Additional packet types should only be defined if the protocol) s
+5 327 M
+(   version number \(see Section ``Protocol Initialization''\) is) s
+5 316 M
+(   incremented, and their use MUST be negotiated using the version) s
+5 305 M
+(   number.  However, the SSH_FXP_EXTENDED and SSH_FXP_EXTENDED_REPLY) s
+5 294 M
+(   packets can be used to implement vendor-specific extensions.  See) s
+5 283 M
+(   Section ``Vendor-Specific-Extensions'' for more details.) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                 [Page 6]) s
+_R
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+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
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+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 7 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
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+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(4. Protocol Initialization) s
+5 668 M
+(   When the file transfer protocol starts, the client first sends a) s
+5 657 M
+(   SSH_FXP_INIT \(including its version number\) packet to the server.) s
+5 646 M
+(   The server responds with a SSH_FXP_VERSION packet, supplying the) s
+5 635 M
+(   lowest of its own and the client's version number.  Both parties) s
+5 624 M
+(   should from then on adhere to particular version of the protocol.) s
+5 602 M
+(   The version number of the protocol specified in this document is 4.) s
+5 591 M
+(   The version number should be incremented for each incompatible) s
+5 580 M
+(   revision of this protocol.) s
+5 558 M
+(4.1 Client Initialization) s
+5 536 M
+(   The SSH_FXP_INIT packet \(from client to server\) has the following) s
+5 525 M
+(   data:) s
+5 503 M
+(                uint32 version) s
+5 481 M
+(   Version 3 of this protocol allowed clients to include extensions in) s
+5 470 M
+(   the SSH_FXP_INIT packet; however, this can cause interoperability) s
+5 459 M
+(   problems with version 1 and version 2 servers because the client must) s
+5 448 M
+(   send this packet before knowing the servers version.) s
+5 426 M
+(   In this version of the protocol, clients MUST use the) s
+5 415 M
+(   SSH_FXP_EXTENDED packet to send extensions to the server after) s
+5 404 M
+(   version exchange has completed.  Clients MUST NOT include extensions) s
+5 393 M
+(   in the version packet.  This will prevent interoperability problems) s
+5 382 M
+(   with older servers) s
+5 360 M
+(4.2 Server Initialization) s
+5 338 M
+(   The SSH_FXP_VERSION packet \(from server to client\) has the following) s
+5 327 M
+(   data:) s
+5 305 M
+(                uint32 version) s
+5 294 M
+(                <extension data>) s
+5 272 M
+(   'version' is the lower of the protocol version supported by the) s
+5 261 M
+(   server and the version number received from the client.) s
+5 239 M
+(   The extension data may be empty, or may be a sequence of) s
+5 217 M
+(                string extension_name) s
+5 206 M
+(                string extension_data) s
+5 184 M
+(   pairs \(both strings MUST always be present if one is, but the) s
+5 173 M
+(   `extension_data' string may be of zero length\).  If present, these) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                 [Page 7]) s
+_R
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+userdict/PStoPSmatrix matrix currentmatrix put
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+%%BeginPageSetup
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+/pagenum 8 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(   strings indicate extensions to the baseline protocol.  The) s
+5 679 M
+(   `extension_name' field\(s\) identify the name of the extension.  The) s
+5 668 M
+(   name should be of the form "name@domain", where the domain is the DNS) s
+5 657 M
+(   domain name of the organization defining the extension.  Additional) s
+5 646 M
+(   names that are not of this format may be defined later by the IETF.) s
+5 635 M
+(   Implementations MUST silently ignore any extensions whose name they) s
+5 624 M
+(   do not recognize.) s
+5 602 M
+(4.3 Determining Server Newline Convention) s
+5 580 M
+(   In order to correctly process text files in a cross platform) s
+5 569 M
+(   compatible way, the newline convention must be converted from that of) s
+5 558 M
+(   the server to that of the client, or, during an upload, from that of) s
+5 547 M
+(   the client to that of the server.) s
+5 525 M
+(   Versions 3 and prior of this protocol made no provisions for) s
+5 514 M
+(   processing text files.  Many clients implemented some sort of) s
+5 503 M
+(   conversion algorithm, but without either a 'canonical' on the wire) s
+5 492 M
+(   format or knowledge of the servers newline convention, correct) s
+5 481 M
+(   conversion was not always possible.) s
+5 459 M
+(   Starting with Version 4, the SSH_FXF_TEXT file open flag \(Section) s
+5 448 M
+(   6.3\) makes it possible to request that the server translate a file to) s
+5 437 M
+(   a 'canonical' on the wire format.  This format uses \\r\\n as the line) s
+5 426 M
+(   separator.) s
+5 404 M
+(   Servers for systems using multiple newline characters \(for example,) s
+5 393 M
+(   Mac OS X or VMS\) or systems using counted records, MUST translate to) s
+5 382 M
+(   the canonical form.) s
+5 360 M
+(   However, to ease the burden of implementation on servers that use a) s
+5 349 M
+(   single, simple separator sequence, the following extension allows the) s
+5 338 M
+(   canonical format to be changed.) s
+5 316 M
+(        string "newline") s
+5 305 M
+(        string new-canonical-separator \(usually "\\r" or "\\n" or "\\r\\n"\)) s
+5 283 M
+(   All clients MUST support this extension.) s
+5 261 M
+(   When processing text files, clients SHOULD NOT translate any) s
+5 250 M
+(   character or sequence that is not an exact match of the servers) s
+5 239 M
+(   newline separator.) s
+5 217 M
+(   In particular, if the newline sequence being used is the canonical) s
+5 206 M
+(   "\\r\\n" sequence, a lone \\r or a lone \\n SHOULD be written through) s
+5 195 M
+(   without change.) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                 [Page 8]) s
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+%%BeginPageSetup
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+/fname () def
+/fdir () def
+/ftail () def
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+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(5. File Attributes) s
+5 668 M
+(   A new compound data type is defined for encoding file attributes.) s
+5 657 M
+(   The same encoding is used both when returning file attributes from) s
+5 646 M
+(   the server and when sending file attributes to the server.  When) s
+5 635 M
+(   sending it to the server, the flags field specifies which attributes) s
+5 624 M
+(   are included, and the server will use default values for the) s
+5 613 M
+(   remaining attributes \(or will not modify the values of remaining) s
+5 602 M
+(   attributes\).  When receiving attributes from the server, the flags) s
+5 591 M
+(   specify which attributes are included in the returned data.  The) s
+5 580 M
+(   server normally returns all attributes it knows about.) s
+5 558 M
+(        uint32   flags) s
+5 547 M
+(        byte     type           always present) s
+5 536 M
+(        uint64   size           present only if flag SSH_FILEXFER_ATTR_SIZE) s
+5 525 M
+(        string   owner          present only if flag SSH_FILEXFER_ATTR_OWNERGROUP) s
+5 514 M
+(        string   group          present only if flag SSH_FILEXFER_ATTR_OWNERGROUP) s
+5 503 M
+(        uint32   permissions    present only if flag SSH_FILEXFER_ATTR_PERMISSIONS) s
+5 492 M
+(        uint32   atime          present only if flag SSH_FILEXFER_ATTR_ACCESSTIME) s
+5 481 M
+(        uint32   createtime     present only if flag SSH_FILEXFER_ATTR_CREATETIME) s
+5 470 M
+(        uint32   mtime          present only if flag SSH_FILEXFER_ATTR_MODIFYTIME) s
+5 459 M
+(        string   acl            present only if flag SSH_FILEXFER_ATTR_ACL) s
+5 448 M
+(        uint32   extended_count present only if flag SSH_FILEXFER_ATTR_EXTENDED) s
+5 437 M
+(        string   extended_type) s
+5 426 M
+(        string   extended_data) s
+5 415 M
+(        ...      more extended data \(extended_type - extended_data pairs\),) s
+5 404 M
+(                   so that number of pairs equals extended_count) s
+5 371 M
+(5.1 Flags) s
+5 349 M
+(   The `flags' specify which of the fields are present.  Those fields) s
+5 338 M
+(   for which the corresponding flag is not set are not present \(not) s
+5 327 M
+(   included in the packet\).  New flags can only be added by incrementing) s
+5 316 M
+(   the protocol version number \(or by using the extension mechanism) s
+5 305 M
+(   described below\).) s
+5 283 M
+(   The flags bits are defined to have the following values:) s
+5 261 M
+(        #define SSH_FILEXFER_ATTR_SIZE            0x00000001) s
+5 250 M
+(        #define SSH_FILEXFER_ATTR_PERMISSIONS     0x00000004) s
+5 239 M
+(        #define SSH_FILEXFER_ATTR_ACCESSTIME      0x00000008) s
+5 228 M
+(        #define SSH_FILEXFER_ATTR_CREATETIME      0x00000010) s
+5 217 M
+(        #define SSH_FILEXFER_ATTR_MODIFYTIME      0x00000020) s
+5 206 M
+(        #define SSH_FILEXFER_ATTR_ACL             0x00000040) s
+5 195 M
+(        #define SSH_FILEXFER_ATTR_OWNERGROUP      0x00000080) s
+5 184 M
+(        #define SSH_FILEXFER_ATTR_EXTENDED        0x80000000) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                 [Page 9]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 10 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(   In previous versions of this protocol flags value 0x00000002 was) s
+5 679 M
+(   SSH_FILEXFER_ATTR_UIDGID.  This value is now unused, and OWNERGROUP) s
+5 668 M
+(   was given a new value in order to ease implementation burden.) s
+5 657 M
+(   0x00000002 MUST NOT appear in the mask.  Some future version of this) s
+5 646 M
+(   protocol may reuse flag 0x00000002.) s
+5 624 M
+(5.2 Type) s
+5 602 M
+(   The type field is always present.  The following types are defined:) s
+5 580 M
+(        #define SSH_FILEXFER_TYPE_REGULAR          1) s
+5 569 M
+(        #define SSH_FILEXFER_TYPE_DIRECTORY        2) s
+5 558 M
+(        #define SSH_FILEXFER_TYPE_SYMLINK          3) s
+5 547 M
+(        #define SSH_FILEXFER_TYPE_SPECIAL          4) s
+5 536 M
+(        #define SSH_FILEXFER_TYPE_UNKNOWN          5) s
+5 514 M
+(   On a POSIX system, these values would be derived from the permission) s
+5 503 M
+(   field.) s
+5 481 M
+(5.3 Size) s
+5 459 M
+(   The `size' field specifies the size of the file on disk, in bytes.) s
+5 448 M
+(   If it is present during file creation, it should be considered a hint) s
+5 437 M
+(   as to the files eventual size.) s
+5 415 M
+(   Files opened with the SSH_FXF_TEXT flag may have a size that is) s
+5 404 M
+(   greater or less than the value of the size field.) s
+5 382 M
+(5.4 Owner and Group) s
+5 360 M
+(   The `owner' and `group' fields are represented as UTF-8 strings; this) s
+5 349 M
+(   is the form used by NFS v4.  See NFS version 4 Protocol.  [3] The) s
+5 338 M
+(   following text is selected quotations from section 5.6.) s
+5 316 M
+(   To avoid a representation that is tied to a particular underlying) s
+5 305 M
+(   implementation at the client or server, the use of UTF-8 strings has) s
+5 294 M
+(   been chosen.  The string should be of the form user@dns_domain".) s
+5 283 M
+(   This will allow for a client and server that do not use the same) s
+5 272 M
+(   local representation the ability to translate to a common syntax that) s
+5 261 M
+(   can be interpreted by both.  In the case where there is no) s
+5 250 M
+(   translation available to the client or server, the attribute value) s
+5 239 M
+(   must be constructed without the "@".  Therefore, the absence of the @) s
+5 228 M
+(   from the owner or owner_group attribute signifies that no translation) s
+5 217 M
+(   was available and the receiver of the attribute should not place any) s
+5 206 M
+(   special meaning with the attribute value.  Even though the attribute) s
+5 195 M
+(   value can not be translated, it may still be useful.  In the case of) s
+5 184 M
+(   a client, the attribute string may be used for local display of) s
+5 173 M
+(   ownership.) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 10]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (10,11) 6
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 11 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(5.5 Permissions) s
+5 668 M
+(   The `permissions' field contains a bit mask of file permissions as) s
+5 657 M
+(   defined by POSIX [1].) s
+5 635 M
+(5.6 Times) s
+5 613 M
+(   The 'atime', 'createtime', and 'mtime' contain the access, creation,) s
+5 602 M
+(   and modification times of the files, respectively.  They are) s
+5 591 M
+(   represented as seconds from Jan 1, 1970 in UTC.) s
+5 569 M
+(5.7 ACL) s
+5 547 M
+(   The 'ACL' field contains an ACL similar to that defined in section) s
+5 536 M
+(   5.9 of NFS version 4 Protocol [3].) s
+5 514 M
+(           uint32   ace-count) s
+5 492 M
+(           repeated ace-count time:) s
+5 481 M
+(                uint32   ace-type) s
+5 470 M
+(                uint32   ace-flag) s
+5 459 M
+(                uint32   ace-mask) s
+5 448 M
+(                string   who [UTF-8]) s
+5 426 M
+(   ace-type is one of the following four values \(taken from NFS Version) s
+5 415 M
+(   4 Protocol [3]:) s
+5 393 M
+(        const ACE4_ACCESS_ALLOWED_ACE_TYPE      = 0x00000000;) s
+5 382 M
+(        const ACE4_ACCESS_DENIED_ACE_TYPE       = 0x00000001;) s
+5 371 M
+(        const ACE4_SYSTEM_AUDIT_ACE_TYPE        = 0x00000002;) s
+5 360 M
+(        const ACE4_SYSTEM_ALARM_ACE_TYPE        = 0x00000003;) s
+5 338 M
+(   ace-flag is a combination of the following flag values.  See NFS) s
+5 327 M
+(   Version 4 Protocol [3] section 5.9.2:) s
+5 305 M
+(        const ACE4_FILE_INHERIT_ACE             = 0x00000001;) s
+5 294 M
+(        const ACE4_DIRECTORY_INHERIT_ACE        = 0x00000002;) s
+5 283 M
+(        const ACE4_NO_PROPAGATE_INHERIT_ACE     = 0x00000004;) s
+5 272 M
+(        const ACE4_INHERIT_ONLY_ACE             = 0x00000008;) s
+5 261 M
+(        const ACE4_SUCCESSFUL_ACCESS_ACE_FLAG   = 0x00000010;) s
+5 250 M
+(        const ACE4_FAILED_ACCESS_ACE_FLAG       = 0x00000020;) s
+5 239 M
+(        const ACE4_IDENTIFIER_GROUP             = 0x00000040;) s
+5 217 M
+(   ace-mask is any combination of the following flags \(taken from NFS) s
+5 206 M
+(   Version 4 Protocol [3] section 5.9.3:) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 11]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 12 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(        const ACE4_READ_DATA            = 0x00000001;) s
+5 679 M
+(        const ACE4_LIST_DIRECTORY       = 0x00000001;) s
+5 668 M
+(        const ACE4_WRITE_DATA           = 0x00000002;) s
+5 657 M
+(        const ACE4_ADD_FILE             = 0x00000002;) s
+5 646 M
+(        const ACE4_APPEND_DATA          = 0x00000004;) s
+5 635 M
+(        const ACE4_ADD_SUBDIRECTORY     = 0x00000004;) s
+5 624 M
+(        const ACE4_READ_NAMED_ATTRS     = 0x00000008;) s
+5 613 M
+(        const ACE4_WRITE_NAMED_ATTRS    = 0x00000010;) s
+5 602 M
+(        const ACE4_EXECUTE              = 0x00000020;) s
+5 591 M
+(        const ACE4_DELETE_CHILD         = 0x00000040;) s
+5 580 M
+(        const ACE4_READ_ATTRIBUTES      = 0x00000080;) s
+5 569 M
+(        const ACE4_WRITE_ATTRIBUTES     = 0x00000100;) s
+5 558 M
+(        const ACE4_DELETE               = 0x00010000;) s
+5 547 M
+(        const ACE4_READ_ACL             = 0x00020000;) s
+5 536 M
+(        const ACE4_WRITE_ACL            = 0x00040000;) s
+5 525 M
+(        const ACE4_WRITE_OWNER          = 0x00080000;) s
+5 514 M
+(        const ACE4_SYNCHRONIZE          = 0x00100000;) s
+5 492 M
+(   who is a UTF-8 string of the form described in 'Owner and Group') s
+5 481 M
+(   \(Section 5.4\)) s
+5 459 M
+(5.8 Extended attributes) s
+5 437 M
+(   The SSH_FILEXFER_ATTR_EXTENDED flag provides a general extension) s
+5 426 M
+(   mechanism for vendor-specific extensions.  If the flag is specified,) s
+5 415 M
+(   then the `extended_count' field is present.  It specifies the number) s
+5 404 M
+(   of extended_type-extended_data pairs that follow.  Each of these) s
+5 393 M
+(   pairs specifies an extended attribute.  For each of the attributes,) s
+5 382 M
+(   the extended_type field should be a string of the format) s
+5 371 M
+(   "name@domain", where "domain" is a valid, registered domain name and) s
+5 360 M
+(   "name" identifies the method.  The IETF may later standardize certain) s
+5 349 M
+(   names that deviate from this format \(e.g., that do not contain the) s
+5 338 M
+(   "@" sign\).  The interpretation of `extended_data' depends on the) s
+5 327 M
+(   type.  Implementations SHOULD ignore extended data fields that they) s
+5 316 M
+(   do not understand.) s
+5 294 M
+(   Additional fields can be added to the attributes by either defining) s
+5 283 M
+(   additional bits to the flags field to indicate their presence, or by) s
+5 272 M
+(   defining extended attributes for them.  The extended attributes) s
+5 261 M
+(   mechanism is recommended for most purposes; additional flags bits) s
+5 250 M
+(   should only be defined by an IETF standards action that also) s
+5 239 M
+(   increments the protocol version number.  The use of such new fields) s
+5 228 M
+(   MUST be negotiated by the version number in the protocol exchange.) s
+5 217 M
+(   It is a protocol error if a packet with unsupported protocol bits is) s
+5 206 M
+(   received.) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 12]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (12,13) 7
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 13 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(6. Requests From the Client to the Server) s
+5 668 M
+(   Requests from the client to the server represent the various file) s
+5 657 M
+(   system operations.  Each request begins with an `id' field, which is) s
+5 646 M
+(   a 32-bit identifier identifying the request \(selected by the client\).) s
+5 635 M
+(   The same identifier will be returned in the response to the request.) s
+5 624 M
+(   One possible implementation is a monotonically increasing request) s
+5 613 M
+(   sequence number \(modulo 2^32\).) s
+5 591 M
+(   Many operations in the protocol operate on open files.  The) s
+5 580 M
+(   SSH_FXP_OPEN request can return a file handle \(which is an opaque) s
+5 569 M
+(   variable-length string\) which may be used to access the file later) s
+5 558 M
+(   \(e.g.  in a read operation\).  The client MUST NOT send requests the) s
+5 547 M
+(   server with bogus or closed handles.  However, the server MUST) s
+5 536 M
+(   perform adequate checks on the handle in order to avoid security) s
+5 525 M
+(   risks due to fabricated handles.) s
+5 503 M
+(   This design allows either stateful and stateless server) s
+5 492 M
+(   implementation, as well as an implementation which caches state) s
+5 481 M
+(   between requests but may also flush it.  The contents of the file) s
+5 470 M
+(   handle string are entirely up to the server and its design.  The) s
+5 459 M
+(   client should not modify or attempt to interpret the file handle) s
+5 448 M
+(   strings.) s
+5 426 M
+(   The file handle strings MUST NOT be longer than 256 bytes.) s
+5 404 M
+(6.1 Request Synchronization and Reordering) s
+5 382 M
+(   The protocol and implementations MUST process requests relating to) s
+5 371 M
+(   the same file in the order in which they are received.  In other) s
+5 360 M
+(   words, if an application submits multiple requests to the server, the) s
+5 349 M
+(   results in the responses will be the same as if it had sent the) s
+5 338 M
+(   requests one at a time and waited for the response in each case.  For) s
+5 327 M
+(   example, the server may process non-overlapping read/write requests) s
+5 316 M
+(   to the same file in parallel, but overlapping reads and writes cannot) s
+5 305 M
+(   be reordered or parallelized.  However, there are no ordering) s
+5 294 M
+(   restrictions on the server for processing requests from two different) s
+5 283 M
+(   file transfer connections.  The server may interleave and parallelize) s
+5 272 M
+(   them at will.) s
+5 250 M
+(   There are no restrictions on the order in which responses to) s
+5 239 M
+(   outstanding requests are delivered to the client, except that the) s
+5 228 M
+(   server must ensure fairness in the sense that processing of no) s
+5 217 M
+(   request will be indefinitely delayed even if the client is sending) s
+5 206 M
+(   other requests so that there are multiple outstanding requests all) s
+5 195 M
+(   the time.) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 13]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 14 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(6.2 File Names) s
+5 668 M
+(   This protocol represents file names as strings.  File names are) s
+5 657 M
+(   assumed to use the slash \('/'\) character as a directory separator.) s
+5 635 M
+(   File names starting with a slash are "absolute", and are relative to) s
+5 624 M
+(   the root of the file system.  Names starting with any other character) s
+5 613 M
+(   are relative to the user's default directory \(home directory\).  Note) s
+5 602 M
+(   that identifying the user is assumed to take place outside of this) s
+5 591 M
+(   protocol.) s
+5 569 M
+(   Servers SHOULD interpret a path name component ".." as referring to) s
+5 558 M
+(   the parent directory, and "." as referring to the current directory.) s
+5 547 M
+(   If the server implementation limits access to certain parts of the) s
+5 536 M
+(   file system, it must be extra careful in parsing file names when) s
+5 525 M
+(   enforcing such restrictions.  There have been numerous reported) s
+5 514 M
+(   security bugs where a ".." in a path name has allowed access outside) s
+5 503 M
+(   the intended area.) s
+5 481 M
+(   An empty path name is valid, and it refers to the user's default) s
+5 470 M
+(   directory \(usually the user's home directory\).) s
+5 448 M
+(   Otherwise, no syntax is defined for file names by this specification.) s
+5 437 M
+(   Clients should not make any other assumptions; however, they can) s
+5 426 M
+(   splice path name components returned by SSH_FXP_READDIR together) s
+5 415 M
+(   using a slash \('/'\) as the separator, and that will work as expected.) s
+5 393 M
+(   In order to comply with IETF Policy on Character Sets and Languages) s
+5 382 M
+(   [2], all filenames are to be encoded in UTF-8.  The shortest valid) s
+5 371 M
+(   UTF-8 encoding of the UNICODE data MUST be used.  The server is) s
+5 360 M
+(   responsible for converting the UNICODE data to whatever canonical) s
+5 349 M
+(   form it requires.) s
+5 327 M
+(   For example, if the server requires that precomposed characters) s
+5 316 M
+(   always be used, the server MUST NOT assume the filename as sent by) s
+5 305 M
+(   the client has this attribute, but must do this normalization itself.) s
+5 283 M
+(   It is understood that the lack of well-defined semantics for file) s
+5 272 M
+(   names may cause interoperability problems between clients and servers) s
+5 261 M
+(   using radically different operating systems.  However, this approach) s
+5 250 M
+(   is known to work acceptably with most systems, and alternative) s
+5 239 M
+(   approaches that e.g.  treat file names as sequences of structured) s
+5 228 M
+(   components are quite complicated.) s
+5 206 M
+(6.3 Opening, Creating, and Closing Files) s
+5 184 M
+(   Files are opened and created using the SSH_FXP_OPEN message, whose) s
+5 173 M
+(   data part is as follows:) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 14]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (14,15) 8
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 15 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(        uint32        id) s
+5 679 M
+(        string        filename [UTF-8]) s
+5 668 M
+(        uint32        pflags) s
+5 657 M
+(        ATTRS         attrs) s
+5 635 M
+(   The `id' field is the request identifier as for all requests.) s
+5 613 M
+(   The `filename' field specifies the file name.  See Section ``File) s
+5 602 M
+(   Names'' for more information.) s
+5 580 M
+(   The `pflags' field is a bitmask.  The following bits have been) s
+5 569 M
+(   defined.) s
+5 547 M
+(        #define SSH_FXF_READ            0x00000001) s
+5 536 M
+(        #define SSH_FXF_WRITE           0x00000002) s
+5 525 M
+(        #define SSH_FXF_APPEND          0x00000004) s
+5 514 M
+(        #define SSH_FXF_CREAT           0x00000008) s
+5 503 M
+(        #define SSH_FXF_TRUNC           0x00000010) s
+5 492 M
+(        #define SSH_FXF_EXCL            0x00000020) s
+5 481 M
+(        #define SSH_FXF_TEXT            0x00000040) s
+5 459 M
+(   These have the following meanings:) s
+5 437 M
+(   SSH_FXF_READ) s
+5 426 M
+(      Open the file for reading.) s
+5 404 M
+(   SSH_FXF_WRITE) s
+5 393 M
+(      Open the file for writing.  If both this and SSH_FXF_READ are) s
+5 382 M
+(      specified, the file is opened for both reading and writing.) s
+5 360 M
+(   SSH_FXF_APPEND) s
+5 349 M
+(      Force all writes to append data at the end of the file.  The) s
+5 338 M
+(      offset parameter to write will be ignored.) s
+5 316 M
+(   SSH_FXF_CREAT) s
+5 305 M
+(      If this flag is specified, then a new file will be created if one) s
+5 294 M
+(      does not already exist \(if O_TRUNC is specified, the new file will) s
+5 283 M
+(      be truncated to zero length if it previously exists\).) s
+5 261 M
+(   SSH_FXF_TRUNC) s
+5 250 M
+(      Forces an existing file with the same name to be truncated to zero) s
+5 239 M
+(      length when creating a file by specifying SSH_FXF_CREAT.) s
+5 228 M
+(      SSH_FXF_CREAT MUST also be specified if this flag is used.) s
+5 206 M
+(   SSH_FXF_EXCL) s
+5 195 M
+(      Causes the request to fail if the named file already exists.) s
+5 184 M
+(      SSH_FXF_CREAT MUST also be specified if this flag is used.) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 15]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 16 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(   SSH_FXF_TEXT) s
+5 679 M
+(      Indicates that the server should treat the file as text and) s
+5 668 M
+(      convert it to the canonical newline convention in use.  \(See) s
+5 657 M
+(      Determining Server Newline Convention. \(Section 4.3\)) s
+5 635 M
+(      When a file is opened with the FXF_TEXT flag, the offset field in) s
+5 624 M
+(      both the read and write function are ignored.) s
+5 602 M
+(      Servers MUST correctly process multiple parallel reads and writes) s
+5 591 M
+(      correctly in this mode.  Naturally, it is permissible for them to) s
+5 580 M
+(      do this by serializing the requests.  It would not be possible for) s
+5 569 M
+(      a client to reliably detect a server that does not implement) s
+5 558 M
+(      parallel writes in time to prevent damage.) s
+5 536 M
+(      Clients SHOULD use the SSH_FXF_APPEND flag to append data to a) s
+5 525 M
+(      text file rather then using write with a calculated offset.) s
+5 503 M
+(      To support seeks on text file the following SSH_FXP_EXTENDED) s
+5 492 M
+(      packet is defined.) s
+5 448 M
+(        string "text-seek") s
+5 437 M
+(        string file-handle) s
+5 426 M
+(        uint64 line-number) s
+5 404 M
+(      line-number is the index of the line number to seek to, where byte) s
+5 393 M
+(      0 in the file is line number 0, and the byte directly following) s
+5 382 M
+(      the first newline sequence in the file is line number 1 and so on.) s
+5 360 M
+(      The response to a "text-seek" request is an SSH_FXP_STATUS) s
+5 349 M
+(      message.) s
+5 327 M
+(      An attempt to seek past the end-of-file should result in a) s
+5 316 M
+(      SSH_FX_EOF status.) s
+5 294 M
+(      Servers SHOULD support at least one "text-seek" in order to) s
+5 283 M
+(      support resume.  However, a client MUST be prepared to receive) s
+5 272 M
+(      SSH_FX_OP_UNSUPPORTED when attempting a "text-seek" operation.) s
+5 261 M
+(      The client can then try a fall-back strategy, if it has one.) s
+5 239 M
+(      Clients MUST be prepared to handle SSH_FX_OP_UNSUPPORTED returned) s
+5 228 M
+(      for read or write operations that are not sequential.) s
+5 206 M
+(   The `attrs' field specifies the initial attributes for the file.) s
+5 195 M
+(   Default values will be used for those attributes that are not) s
+5 184 M
+(   specified.  See Section ``File Attributes'' for more information.) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 16]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (16,17) 9
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 17 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(   The response to this message will be either SSH_FXP_HANDLE \(if the) s
+5 679 M
+(   operation is successful\) or SSH_FXP_STATUS \(if the operation fails\).) s
+5 657 M
+(   A file is closed by using the SSH_FXP_CLOSE request.  Its data field) s
+5 646 M
+(   has the following format:) s
+5 624 M
+(        uint32     id) s
+5 613 M
+(        string     handle) s
+5 591 M
+(   where `id' is the request identifier, and `handle' is a handle) s
+5 580 M
+(   previously returned in the response to SSH_FXP_OPEN or) s
+5 569 M
+(   SSH_FXP_OPENDIR.  The handle becomes invalid immediately after this) s
+5 558 M
+(   request has been sent.) s
+5 536 M
+(   The response to this request will be a SSH_FXP_STATUS message.  One) s
+5 525 M
+(   should note that on some server platforms even a close can fail.) s
+5 514 M
+(   This can happen e.g.  if the server operating system caches writes,) s
+5 503 M
+(   and an error occurs while flushing cached writes during the close.) s
+5 481 M
+(6.4 Reading and Writing) s
+5 459 M
+(   Once a file has been opened, it can be read using the SSH_FXP_READ) s
+5 448 M
+(   message, which has the following format:) s
+5 426 M
+(        uint32     id) s
+5 415 M
+(        string     handle) s
+5 404 M
+(        uint64     offset) s
+5 393 M
+(        uint32     len) s
+5 371 M
+(   where `id' is the request identifier, `handle' is an open file handle) s
+5 360 M
+(   returned by SSH_FXP_OPEN, `offset' is the offset \(in bytes\) relative) s
+5 349 M
+(   to the beginning of the file from where to start reading, and `len') s
+5 338 M
+(   is the maximum number of bytes to read.) s
+5 316 M
+(   In response to this request, the server will read as many bytes as it) s
+5 305 M
+(   can from the file \(up to `len'\), and return them in a SSH_FXP_DATA) s
+5 294 M
+(   message.  If an error occurs or EOF is encountered before reading any) s
+5 283 M
+(   data, the server will respond with SSH_FXP_STATUS.  For normal disk) s
+5 272 M
+(   files, it is guaranteed that this will read the specified number of) s
+5 261 M
+(   bytes, or up to end of file.  For e.g.  device files this may return) s
+5 250 M
+(   fewer bytes than requested.) s
+5 228 M
+(   Writing to a file is achieved using the SSH_FXP_WRITE message, which) s
+5 217 M
+(   has the following format:) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 17]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 18 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(        uint32     id) s
+5 679 M
+(        string     handle) s
+5 668 M
+(        uint64     offset) s
+5 657 M
+(        string     data) s
+5 635 M
+(   where `id' is a request identifier, `handle' is a file handle) s
+5 624 M
+(   returned by SSH_FXP_OPEN, `offset' is the offset \(in bytes\) from the) s
+5 613 M
+(   beginning of the file where to start writing, and `data' is the data) s
+5 602 M
+(   to be written.) s
+5 580 M
+(   The write will extend the file if writing beyond the end of the file.) s
+5 569 M
+(   It is legal to write way beyond the end of the file; the semantics) s
+5 558 M
+(   are to write zeroes from the end of the file to the specified offset) s
+5 547 M
+(   and then the data.  On most operating systems, such writes do not) s
+5 536 M
+(   allocate disk space but instead leave "holes" in the file.) s
+5 514 M
+(   The server responds to a write request with a SSH_FXP_STATUS message.) s
+5 492 M
+(6.5 Removing and Renaming Files) s
+5 470 M
+(   Files can be removed using the SSH_FXP_REMOVE message.  It has the) s
+5 459 M
+(   following format:) s
+5 437 M
+(        uint32     id) s
+5 426 M
+(        string     filename [UTF-8]) s
+5 404 M
+(   where `id' is the request identifier and `filename' is the name of) s
+5 393 M
+(   the file to be removed.  See Section ``File Names'' for more) s
+5 382 M
+(   information.  This request cannot be used to remove directories.) s
+5 360 M
+(   The server will respond to this request with a SSH_FXP_STATUS) s
+5 349 M
+(   message.) s
+5 327 M
+(   Files \(and directories\) can be renamed using the SSH_FXP_RENAME) s
+5 316 M
+(   message.  Its data is as follows:) s
+5 294 M
+(        uint32     id) s
+5 283 M
+(        string     oldpath [UTF-8]) s
+5 272 M
+(        string     newpath [UTF-8]) s
+5 250 M
+(   where `id' is the request identifier, `oldpath' is the name of an) s
+5 239 M
+(   existing file or directory, and `newpath' is the new name for the) s
+5 228 M
+(   file or directory.  It is an error if there already exists a file) s
+5 217 M
+(   with the name specified by newpath.  The server may also fail rename) s
+5 206 M
+(   requests in other situations, for example if `oldpath' and `newpath') s
+5 195 M
+(   point to different file systems on the server.) s
+5 173 M
+(   The server will respond to this request with a SSH_FXP_STATUS) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 18]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (18,19) 10
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 19 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(   message.) s
+5 668 M
+(6.6 Creating and Deleting Directories) s
+5 646 M
+(   New directories can be created using the SSH_FXP_MKDIR request.  It) s
+5 635 M
+(   has the following format:) s
+5 613 M
+(        uint32     id) s
+5 602 M
+(        string     path [UTF-8]) s
+5 591 M
+(        ATTRS      attrs) s
+5 569 M
+(   where `id' is the request identifier.) s
+5 547 M
+(   `path' specifies the directory to be created.  See Section ``File) s
+5 536 M
+(   Names'' for more information on file names.) s
+5 514 M
+(   `attrs' specifies the attributes that should be applied to it upon) s
+5 503 M
+(   creation.  Attributes are discussed in more detail in Section ``File) s
+5 492 M
+(   Attributes''.) s
+5 470 M
+(   The server will respond to this request with a SSH_FXP_STATUS) s
+5 459 M
+(   message.  If a file or directory with the specified path already) s
+5 448 M
+(   exists, an error will be returned.) s
+5 426 M
+(   Directories can be removed using the SSH_FXP_RMDIR request, which has) s
+5 415 M
+(   the following format:) s
+5 393 M
+(        uint32     id) s
+5 382 M
+(        string     path [UTF-8]) s
+5 360 M
+(   where `id' is the request identifier, and `path' specifies the) s
+5 349 M
+(   directory to be removed.  See Section ``File Names'' for more) s
+5 338 M
+(   information on file names.) s
+5 316 M
+(   The server responds to this request with a SSH_FXP_STATUS message.) s
+5 305 M
+(   Errors may be returned from this operation for various reasons,) s
+5 294 M
+(   including, but not limited to, the path does not exist, the path does) s
+5 283 M
+(   not refer to a directory object, the directory is not empty, or the) s
+5 272 M
+(   user has insufficient access or permission to perform the requested) s
+5 261 M
+(   operation.) s
+5 239 M
+(6.7 Scanning Directories) s
+5 217 M
+(   The files in a directory can be listed using the SSH_FXP_OPENDIR and) s
+5 206 M
+(   SSH_FXP_READDIR requests.  Each SSH_FXP_READDIR request returns one) s
+5 195 M
+(   or more file names with full file attributes for each file.  The) s
+5 184 M
+(   client should call SSH_FXP_READDIR repeatedly until it has found the) s
+5 173 M
+(   file it is looking for or until the server responds with a) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 19]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 20 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(   SSH_FXP_STATUS message indicating an error \(normally SSH_FX_EOF if) s
+5 679 M
+(   there are no more files in the directory\).  The client should then) s
+5 668 M
+(   close the handle using the SSH_FXP_CLOSE request.) s
+5 646 M
+(   The SSH_FXP_OPENDIR opens a directory for reading.  It has the) s
+5 635 M
+(   following format:) s
+5 613 M
+(        uint32     id) s
+5 602 M
+(        string     path [UTF-8]) s
+5 580 M
+(   where `id' is the request identifier and `path' is the path name of) s
+5 569 M
+(   the directory to be listed \(without any trailing slash\).  See Section) s
+5 558 M
+(   ``File Names'' for more information on file names.  This will return) s
+5 547 M
+(   an error if the path does not specify a directory or if the directory) s
+5 536 M
+(   is not readable.  The server will respond to this request with either) s
+5 525 M
+(   a SSH_FXP_HANDLE or a SSH_FXP_STATUS message.) s
+5 503 M
+(   Once the directory has been successfully opened, files \(and) s
+5 492 M
+(   directories\) contained in it can be listed using SSH_FXP_READDIR) s
+5 481 M
+(   requests.  These are of the format) s
+5 459 M
+(        uint32     id) s
+5 448 M
+(        string     handle) s
+5 426 M
+(   where `id' is the request identifier, and `handle' is a handle) s
+5 415 M
+(   returned by SSH_FXP_OPENDIR.  \(It is a protocol error to attempt to) s
+5 404 M
+(   use an ordinary file handle returned by SSH_FXP_OPEN.\)) s
+5 382 M
+(   The server responds to this request with either a SSH_FXP_NAME or a) s
+5 371 M
+(   SSH_FXP_STATUS message.  One or more names may be returned at a time.) s
+5 360 M
+(   Full status information is returned for each name in order to speed) s
+5 349 M
+(   up typical directory listings.) s
+5 327 M
+(   If there are no more names available to be read, the server MUST) s
+5 316 M
+(   respond with a SSH_FXP_STATUS message with error code of SSH_FX_EOF.) s
+5 294 M
+(   When the client no longer wishes to read more names from the) s
+5 283 M
+(   directory, it SHOULD call SSH_FXP_CLOSE for the handle.  The handle) s
+5 272 M
+(   should be closed regardless of whether an error has occurred or not.) s
+5 250 M
+(6.8 Retrieving File Attributes) s
+5 228 M
+(   Very often, file attributes are automatically returned by) s
+5 217 M
+(   SSH_FXP_READDIR.  However, sometimes there is need to specifically) s
+5 206 M
+(   retrieve the attributes for a named file.  This can be done using the) s
+5 195 M
+(   SSH_FXP_STAT, SSH_FXP_LSTAT and SSH_FXP_FSTAT requests.) s
+5 173 M
+(   SSH_FXP_STAT and SSH_FXP_LSTAT only differ in that SSH_FXP_STAT) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 20]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (20,21) 11
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 21 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(   follows symbolic links on the server, whereas SSH_FXP_LSTAT does not) s
+5 679 M
+(   follow symbolic links.  Both have the same format:) s
+5 657 M
+(        uint32     id) s
+5 646 M
+(        string     path [UTF-8]) s
+5 635 M
+(        uint32     flags) s
+5 613 M
+(   where `id' is the request identifier, and `path' specifies the file) s
+5 602 M
+(   system object for which status is to be returned.  The server) s
+5 591 M
+(   responds to this request with either SSH_FXP_ATTRS or SSH_FXP_STATUS.) s
+5 569 M
+(   The flags field specify the attribute flags in which the client has) s
+5 558 M
+(   particular interest.  This is a hint to the server.  For example,) s
+5 547 M
+(   because retrieving owner / group and acl information can be an) s
+5 536 M
+(   expensive operation under some operating systems, the server may) s
+5 525 M
+(   choose not to retrieve this information unless the client expresses a) s
+5 514 M
+(   specific interest in it.) s
+5 492 M
+(   The client has no guarantee the server will provide all the fields) s
+5 481 M
+(   that it has expressed an interest in.) s
+5 459 M
+(   SSH_FXP_FSTAT differs from the others in that it returns status) s
+5 448 M
+(   information for an open file \(identified by the file handle\).  Its) s
+5 437 M
+(   format is as follows:) s
+5 415 M
+(        uint32     id) s
+5 404 M
+(        string     handle) s
+5 393 M
+(        uint32     flags) s
+5 371 M
+(   where `id' is the request identifier and `handle' is a file handle) s
+5 360 M
+(   returned by SSH_FXP_OPEN.  The server responds to this request with) s
+5 349 M
+(   SSH_FXP_ATTRS or SSH_FXP_STATUS.) s
+5 327 M
+(6.9 Setting File Attributes) s
+5 305 M
+(   File attributes may be modified using the SSH_FXP_SETSTAT and) s
+5 294 M
+(   SSH_FXP_FSETSTAT requests.  These requests are used for operations) s
+5 283 M
+(   such as changing the ownership, permissions or access times, as well) s
+5 272 M
+(   as for truncating a file.) s
+5 250 M
+(   The SSH_FXP_SETSTAT request is of the following format:) s
+5 228 M
+(        uint32     id) s
+5 217 M
+(        string     path [UTF-8]) s
+5 206 M
+(        ATTRS      attrs) s
+5 184 M
+(   where `id' is the request identifier, `path' specifies the file) s
+5 173 M
+(   system object \(e.g.  file or directory\) whose attributes are to be) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 21]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 22 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(   modified, and `attrs' specifies the modifications to be made to its) s
+5 679 M
+(   attributes.  Attributes are discussed in more detail in Section) s
+5 668 M
+(   ``File Attributes''.) s
+5 646 M
+(   An error will be returned if the specified file system object does) s
+5 635 M
+(   not exist or the user does not have sufficient rights to modify the) s
+5 624 M
+(   specified attributes.  The server responds to this request with a) s
+5 613 M
+(   SSH_FXP_STATUS message.) s
+5 591 M
+(   The SSH_FXP_FSETSTAT request modifies the attributes of a file which) s
+5 580 M
+(   is already open.  It has the following format:) s
+5 558 M
+(        uint32     id) s
+5 547 M
+(        string     handle) s
+5 536 M
+(        ATTRS      attrs) s
+5 514 M
+(   where `id' is the request identifier, `handle' \(MUST be returned by) s
+5 503 M
+(   SSH_FXP_OPEN\) identifies the file whose attributes are to be) s
+5 492 M
+(   modified, and `attrs' specifies the modifications to be made to its) s
+5 481 M
+(   attributes.  Attributes are discussed in more detail in Section) s
+5 470 M
+(   ``File Attributes''.  The server will respond to this request with) s
+5 459 M
+(   SSH_FXP_STATUS.) s
+5 437 M
+(6.10 Dealing with Symbolic links) s
+5 415 M
+(   The SSH_FXP_READLINK request may be used to read the target of a) s
+5 404 M
+(   symbolic link.  It would have a data part as follows:) s
+5 382 M
+(        uint32     id) s
+5 371 M
+(        string     path [UTF-8]) s
+5 349 M
+(   where `id' is the request identifier and `path' specifies the path) s
+5 338 M
+(   name of the symlink to be read.) s
+5 316 M
+(   The server will respond with a SSH_FXP_NAME packet containing only) s
+5 305 M
+(   one name and a dummy attributes value.  The name in the returned) s
+5 294 M
+(   packet contains the target of the link.  If an error occurs, the) s
+5 283 M
+(   server may respond with SSH_FXP_STATUS.) s
+5 261 M
+(   The SSH_FXP_SYMLINK request will create a symbolic link on the) s
+5 250 M
+(   server.  It is of the following format) s
+5 228 M
+(        uint32     id) s
+5 217 M
+(        string     linkpath   [UTF-8]) s
+5 206 M
+(        string     targetpath [UTF-8]) s
+5 184 M
+(   where `id' is the request identifier, `linkpath' specifies the path) s
+5 173 M
+(   name of the symlink to be created and `targetpath' specifies the) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 22]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (22,23) 12
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 23 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(   target of the symlink.  The server shall respond with a) s
+5 679 M
+(   SSH_FXP_STATUS indicating either success \(SSH_FX_OK\) or an error) s
+5 668 M
+(   condition.) s
+5 646 M
+(6.11 Canonicalizing the Server-Side Path Name) s
+5 624 M
+(   The SSH_FXP_REALPATH request can be used to have the server) s
+5 613 M
+(   canonicalize any given path name to an absolute path.  This is useful) s
+5 602 M
+(   for converting path names containing ".." components or relative) s
+5 591 M
+(   pathnames without a leading slash into absolute paths.  The format of) s
+5 580 M
+(   the request is as follows:) s
+5 558 M
+(        uint32     id) s
+5 547 M
+(        string     path [UTF-8]) s
+5 525 M
+(   where `id' is the request identifier and `path' specifies the path) s
+5 514 M
+(   name to be canonicalized.  The server will respond with a) s
+5 503 M
+(   SSH_FXP_NAME packet containing the name in canonical form and a dummy) s
+5 492 M
+(   attributes value.  If an error occurs, the server may also respond) s
+5 481 M
+(   with SSH_FXP_STATUS.) s
+5 459 M
+(6.11.1 Best practice for dealing with paths) s
+5 437 M
+(   The client SHOULD treat the results of SSH_FXP_REALPATH as a) s
+5 426 M
+(   canonical absolute path, even if the path does not appear to be) s
+5 415 M
+(   absolute.  A client that use REALPATH\("."\) and treats the result as) s
+5 404 M
+(   absolute, even if there is no leading slash, will continue to) s
+5 393 M
+(   function correctly, even when talking to a Windows NT or VMS style) s
+5 382 M
+(   system, where absolute paths may not begin with a slash.) s
+5 360 M
+(   For example, if the client wishes to change directory up, and the) s
+5 349 M
+(   server has returned "c:/x/y/z" from REALPATH, the client SHOULD use) s
+5 338 M
+(   "c:/x/y/z/..".) s
+5 316 M
+(   As a second example, if the client wishes to open the file "x.txt" in) s
+5 305 M
+(   the current directory, and server has returned "dka100:/x/y/z" as the) s
+5 294 M
+(   canonical path of the directory, the client SHOULD open "dka100:/x/y/) s
+5 283 M
+(   z/x.txt") s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 23]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 24 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(7. Responses from the Server to the Client) s
+5 668 M
+(   The server responds to the client using one of a few response) s
+5 657 M
+(   packets.  All requests can return a SSH_FXP_STATUS response upon) s
+5 646 M
+(   failure.  When the operation is successful, any of the responses may) s
+5 635 M
+(   be returned \(depending on the operation\).  If no data needs to be) s
+5 624 M
+(   returned to the client, the SSH_FXP_STATUS response with SSH_FX_OK) s
+5 613 M
+(   status is appropriate.  Otherwise, the SSH_FXP_HANDLE message is used) s
+5 602 M
+(   to return a file handle \(for SSH_FXP_OPEN and SSH_FXP_OPENDIR) s
+5 591 M
+(   requests\), SSH_FXP_DATA is used to return data from SSH_FXP_READ,) s
+5 580 M
+(   SSH_FXP_NAME is used to return one or more file names from a) s
+5 569 M
+(   SSH_FXP_READDIR or SSH_FXP_REALPATH request, and SSH_FXP_ATTRS is) s
+5 558 M
+(   used to return file attributes from SSH_FXP_STAT, SSH_FXP_LSTAT, and) s
+5 547 M
+(   SSH_FXP_FSTAT requests.) s
+5 525 M
+(   Exactly one response will be returned for each request.  Each) s
+5 514 M
+(   response packet contains a request identifier which can be used to) s
+5 503 M
+(   match each response with the corresponding request.  Note that it is) s
+5 492 M
+(   legal to have several requests outstanding simultaneously, and the) s
+5 481 M
+(   server is allowed to send responses to them in a different order from) s
+5 470 M
+(   the order in which the requests were sent \(the result of their) s
+5 459 M
+(   execution, however, is guaranteed to be as if they had been processed) s
+5 448 M
+(   one at a time in the order in which the requests were sent\).) s
+5 426 M
+(   Response packets are of the same general format as request packets.) s
+5 415 M
+(   Each response packet begins with the request identifier.) s
+5 393 M
+(   The format of the data portion of the SSH_FXP_STATUS response is as) s
+5 382 M
+(   follows:) s
+5 360 M
+(        uint32     id) s
+5 349 M
+(        uint32     error/status code) s
+5 338 M
+(        string     error message \(ISO-10646 UTF-8 [RFC-2279]\)) s
+5 327 M
+(        string     language tag \(as defined in [RFC-1766]\)) s
+5 305 M
+(   where `id' is the request identifier, and `error/status code') s
+5 294 M
+(   indicates the result of the requested operation.  The value SSH_FX_OK) s
+5 283 M
+(   indicates success, and all other values indicate failure.) s
+5 261 M
+(   Currently, the following values are defined \(other values may be) s
+5 250 M
+(   defined by future versions of this protocol\):) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 24]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (24,25) 13
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 25 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(        #define SSH_FX_OK                            0) s
+5 679 M
+(        #define SSH_FX_EOF                           1) s
+5 668 M
+(        #define SSH_FX_NO_SUCH_FILE                  2) s
+5 657 M
+(        #define SSH_FX_PERMISSION_DENIED             3) s
+5 646 M
+(        #define SSH_FX_FAILURE                       4) s
+5 635 M
+(        #define SSH_FX_BAD_MESSAGE                   5) s
+5 624 M
+(        #define SSH_FX_NO_CONNECTION                 6) s
+5 613 M
+(        #define SSH_FX_CONNECTION_LOST               7) s
+5 602 M
+(        #define SSH_FX_OP_UNSUPPORTED                8) s
+5 591 M
+(        #define SSH_FX_INVALID_HANDLE                9) s
+5 580 M
+(        #define SSH_FX_NO_SUCH_PATH                  10) s
+5 569 M
+(        #define SSH_FX_FILE_ALREADY_EXISTS                       11) s
+5 558 M
+(        #define SSH_FX_WRITE_PROTECT                             12) s
+5 536 M
+(   SSH_FX_OK) s
+5 525 M
+(      Indicates successful completion of the operation.) s
+5 503 M
+(   SSH_FX_EOF) s
+5 492 M
+(      indicates end-of-file condition; for SSH_FX_READ it means that no) s
+5 481 M
+(      more data is available in the file, and for SSH_FX_READDIR it) s
+5 470 M
+(      indicates that no more files are contained in the directory.) s
+5 448 M
+(   SSH_FX_NO_SUCH_FILE) s
+5 437 M
+(      is returned when a reference is made to a file which does not) s
+5 426 M
+(      exist.) s
+5 404 M
+(   SSH_FX_PERMISSION_DENIED) s
+5 393 M
+(      is returned when the authenticated user does not have sufficient) s
+5 382 M
+(      permissions to perform the operation.) s
+5 360 M
+(   SSH_FX_FAILURE) s
+5 349 M
+(      is a generic catch-all error message; it should be returned if an) s
+5 338 M
+(      error occurs for which there is no more specific error code) s
+5 327 M
+(      defined.) s
+5 305 M
+(   SSH_FX_BAD_MESSAGE) s
+5 294 M
+(      may be returned if a badly formatted packet or protocol) s
+5 283 M
+(      incompatibility is detected.) s
+5 261 M
+(   SSH_FX_NO_CONNECTION) s
+5 250 M
+(      is a pseudo-error which indicates that the client has no) s
+5 239 M
+(      connection to the server \(it can only be generated locally by the) s
+5 228 M
+(      client, and MUST NOT be returned by servers\).) s
+5 206 M
+(   SSH_FX_CONNECTION_LOST) s
+5 195 M
+(      is a pseudo-error which indicates that the connection to the) s
+5 184 M
+(      server has been lost \(it can only be generated locally by the) s
+5 173 M
+(      client, and MUST NOT be returned by servers\).) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 25]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 26 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(   SSH_FX_OP_UNSUPPORTED) s
+5 679 M
+(      indicates that an attempt was made to perform an operation which) s
+5 668 M
+(      is not supported for the server \(it may be generated locally by) s
+5 657 M
+(      the client if e.g.  the version number exchange indicates that a) s
+5 646 M
+(      required feature is not supported by the server, or it may be) s
+5 635 M
+(      returned by the server if the server does not implement an) s
+5 624 M
+(      operation\).) s
+5 602 M
+(   SSH_FX_INVALID_HANDLE) s
+5 591 M
+(      The handle value was invalid.) s
+5 569 M
+(   SSH_FX_NO_SUCH_PATH) s
+5 558 M
+(      The file path does not exist or is invalid.) s
+5 536 M
+(   SSH_FX_FILE_ALREADY_EXISTS) s
+5 525 M
+(      The file already exists.) s
+5 503 M
+(   SSH_FX_WRITE_PROTECT) s
+5 492 M
+(      The file is on read only media, or the media is write protected.) s
+5 470 M
+(   The SSH_FXP_HANDLE response has the following format:) s
+5 448 M
+(        uint32     id) s
+5 437 M
+(        string     handle) s
+5 415 M
+(   where `id' is the request identifier, and `handle' is an arbitrary) s
+5 404 M
+(   string that identifies an open file or directory on the server.  The) s
+5 393 M
+(   handle is opaque to the client; the client MUST NOT attempt to) s
+5 382 M
+(   interpret or modify it in any way.  The length of the handle string) s
+5 371 M
+(   MUST NOT exceed 256 data bytes.) s
+5 349 M
+(   The SSH_FXP_DATA response has the following format:) s
+5 327 M
+(        uint32     id) s
+5 316 M
+(        string     data) s
+5 294 M
+(   where `id' is the request identifier, and `data' is an arbitrary byte) s
+5 283 M
+(   string containing the requested data.  The data string may be at most) s
+5 272 M
+(   the number of bytes requested in a SSH_FXP_READ request, but may also) s
+5 261 M
+(   be shorter if end of file is reached or if the read is from something) s
+5 250 M
+(   other than a regular file.) s
+5 228 M
+(   The SSH_FXP_NAME response has the following format:) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 26]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (26,27) 14
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 27 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(        uint32     id) s
+5 679 M
+(        uint32     count) s
+5 668 M
+(        repeats count times:) s
+5 657 M
+(                string     filename [UTF-8]) s
+5 646 M
+(                ATTRS      attrs) s
+5 624 M
+(   where `id' is the request identifier, `count' is the number of names) s
+5 613 M
+(   returned in this response, and the remaining fields repeat `count') s
+5 602 M
+(   times \(so that all three fields are first included for the first) s
+5 591 M
+(   file, then for the second file, etc\).  In the repeated part,) s
+5 580 M
+(   `filename' is a file name being returned \(for SSH_FXP_READDIR, it) s
+5 569 M
+(   will be a relative name within the directory, without any path) s
+5 558 M
+(   components; for SSH_FXP_REALPATH it will be an absolute path name\),) s
+5 547 M
+(   and `attrs' is the attributes of the file as described in Section) s
+5 536 M
+(   ``File Attributes''.) s
+5 514 M
+(   The SSH_FXP_ATTRS response has the following format:) s
+5 492 M
+(        uint32     id) s
+5 481 M
+(        ATTRS      attrs) s
+5 459 M
+(   where `id' is the request identifier, and `attrs' is the returned) s
+5 448 M
+(   file attributes as described in Section ``File Attributes''.) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 27]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 28 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(8. Vendor-Specific Extensions) s
+5 668 M
+(   The SSH_FXP_EXTENDED request provides a generic extension mechanism) s
+5 657 M
+(   for adding vendor-specific commands.  The request has the following) s
+5 646 M
+(   format:) s
+5 624 M
+(        uint32     id) s
+5 613 M
+(        string     extended-request) s
+5 602 M
+(        ... any request-specific data ...) s
+5 580 M
+(   where `id' is the request identifier, and `extended-request' is a) s
+5 569 M
+(   string of the format "name@domain", where domain is an internet) s
+5 558 M
+(   domain name of the vendor defining the request.  The rest of the) s
+5 547 M
+(   request is completely vendor-specific, and servers should only) s
+5 536 M
+(   attempt to interpret it if they recognize the `extended-request') s
+5 525 M
+(   name.) s
+5 503 M
+(   The server may respond to such requests using any of the response) s
+5 492 M
+(   packets defined in Section ``Responses from the Server to the) s
+5 481 M
+(   Client''.  Additionally, the server may also respond with a) s
+5 470 M
+(   SSH_FXP_EXTENDED_REPLY packet, as defined below.  If the server does) s
+5 459 M
+(   not recognize the `extended-request' name, then the server MUST) s
+5 448 M
+(   respond with SSH_FXP_STATUS with error/status set to) s
+5 437 M
+(   SSH_FX_OP_UNSUPPORTED.) s
+5 415 M
+(   The SSH_FXP_EXTENDED_REPLY packet can be used to carry arbitrary) s
+5 404 M
+(   extension-specific data from the server to the client.  It is of the) s
+5 393 M
+(   following format:) s
+5 371 M
+(        uint32     id) s
+5 360 M
+(        ... any request-specific data ...) s
+5 338 M
+(   There is a range of packet types reserved for use by extensions.  In) s
+5 327 M
+(   order to avoid collision, extensions that turn on the use of) s
+5 316 M
+(   additional packet types should determine those numbers dynamically.) s
+5 294 M
+(   The suggested way of doing this is have an extension request from the) s
+5 283 M
+(   client to the server that enables the extension; the extension) s
+5 272 M
+(   response from the server to the client would specify the actual type) s
+5 261 M
+(   values to use, in additional to any other data.) s
+5 239 M
+(   Extension authors should be mindful of the limited range of packet) s
+5 228 M
+(   types available \(there are only 45 values available\) and avoid) s
+5 217 M
+(   requiring a new packet type where possible.) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 28]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (28,29) 15
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 29 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(9. Security Considerations) s
+5 668 M
+(   This protocol assumes that it is run over a secure channel and that) s
+5 657 M
+(   the endpoints of the channel have been authenticated.  Thus, this) s
+5 646 M
+(   protocol assumes that it is externally protected from network-level) s
+5 635 M
+(   attacks.) s
+5 613 M
+(   This protocol provides file system access to arbitrary files on the) s
+5 602 M
+(   server \(only constrained by the server implementation\).  It is the) s
+5 591 M
+(   responsibility of the server implementation to enforce any access) s
+5 580 M
+(   controls that may be required to limit the access allowed for any) s
+5 569 M
+(   particular user \(the user being authenticated externally to this) s
+5 558 M
+(   protocol, typically using the SSH User Authentication Protocol [8].) s
+5 536 M
+(   Care must be taken in the server implementation to check the validity) s
+5 525 M
+(   of received file handle strings.  The server should not rely on them) s
+5 514 M
+(   directly; it MUST check the validity of each handle before relying on) s
+5 503 M
+(   it.) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 29]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 30 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(10. Changes from previous protocol versions) s
+5 668 M
+(   The SSH File Transfer Protocol has changed over time, before it's) s
+5 657 M
+(   standardization.  The following is a description of the incompatible) s
+5 646 M
+(   changes between different versions.) s
+5 624 M
+(10.1 Changes between versions 4 and 3) s
+5 602 M
+(   Many of the changes between version 4 and version 3 are to the) s
+5 591 M
+(   attribute structure to make it more flexible for non-unix platforms.) s
+5 569 M
+(   o  Make all filenames UTF-8.) s
+5 547 M
+(   o  Added 'newline' extension.) s
+5 525 M
+(   o  Made file attribute owner and group strings so they can actually) s
+5 514 M
+(      be used on disparate systems.) s
+5 492 M
+(   o  Added createtime field, and added separate flags for atime,) s
+5 481 M
+(      createtime, and mtime so they can be set separately.) s
+5 459 M
+(   o  Split the file type out of the permissions field and into it's own) s
+5 448 M
+(      field \(which is always present.\)) s
+5 426 M
+(   o  Added acl attribute.) s
+5 404 M
+(   o  Added SSH_FXF_TEXT file open flag.) s
+5 382 M
+(   o  Added flags field to the get stat commands so that the client can) s
+5 371 M
+(      specifically request information the server might not normally) s
+5 360 M
+(      included for performance reasons.) s
+5 338 M
+(   o  Removed the long filename from the names structure-- it can now be) s
+5 327 M
+(      built from information available in the attrs structure.) s
+5 305 M
+(   o  Added reserved range of packet numbers for extensions.) s
+5 283 M
+(   o  Added several additional error codes.) s
+5 261 M
+(   o  Change the way version negotiate works slightly.  Previously, if) s
+5 250 M
+(      the client version were higher than the server version, the server) s
+5 239 M
+(      was supposed to 'echo back' the clients version.  The server now) s
+5 228 M
+(      sends it's own version and the lower of the two is considered to) s
+5 217 M
+(      be the one in use.) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 30]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (30,31) 16
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 31 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(10.2 Changes between versions 3 and 2) s
+5 668 M
+(   o  The SSH_FXP_READLINK and SSH_FXP_SYMLINK messages were added.) s
+5 646 M
+(   o  The SSH_FXP_EXTENDED and SSH_FXP_EXTENDED_REPLY messages were) s
+5 635 M
+(      added.) s
+5 613 M
+(   o  The SSH_FXP_STATUS message was changed to include fields `error) s
+5 602 M
+(      message' and `language tag'.) s
+5 569 M
+(10.3 Changes between versions 2 and 1) s
+5 547 M
+(   o  The SSH_FXP_RENAME message was added.) s
+5 514 M
+(10.4 Changes between versions 1 and 0) s
+5 492 M
+(   o  Implementation changes, no actual protocol changes.) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 31]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 32 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(11. Trademark Issues) s
+5 668 M
+(   "ssh" is a registered trademark of SSH Communications Security Corp) s
+5 657 M
+(   in the United States and/or other countries.) s
+5 129 M
+(Galbraith, et al.        Expires April 16, 2003                [Page 32]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (32,33) 17
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 33 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft         SSH File Transfer Protocol           October 2002) s
+5 690 M
+(References) s
+5 668 M
+(   [1]  Dierks, T., Allen, C., Treese, W., Karlton, P., Freier, A. and) s
+5 657 M
+(        P. Kocher, "The TLS Protocol Version 1.0", RFC 2246, January) s
+5 646 M
+(        1999.) s
+5 624 M
+(   [2]  Alvestrand, H., "IETF Policy on Character Sets and Languages",) s
+5 613 M
+(        BCP 18, RFC 2277, January 1998.) s
+5 591 M
+(   [3]  Shepler, S., Callaghan, B., Robinson, D., Thurlow, R., Beame,) s
+5 580 M
+(        C., Eisler, M. and D. Noveck, "NFS version 4 Protocol", RFC) s
+5 569 M
+(        3010, December 2000.) s
+5 547 M
+(   [4]  Institute of Electrical and Electronics Engineers, "Information) s
+5 536 M
+(        Technology - Portable Operating System Interface \(POSIX\) - Part) s
+5 525 M
+(        1: System Application Program Interface \(API\) [C Language]",) s
+5 514 M
+(        IEEE Standard 1003.2, 1996.) s
+5 492 M
+(   [5]  Rinne, T., Ylonen, T., Kivinen, T., Saarinen, M. and S.) s
+5 481 M
+(        Lehtinen, "SSH Protocol Architecture", draft-ietf-secsh-) s
+5 470 M
+(        architecture-13 \(work in progress\), September 2002.) s
+5 448 M
+(   [6]  Rinne, T., Ylonen, T., Kivinen, T., Saarinen, M. and S.) s
+5 437 M
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+(Full Copyright Statement) s
+5 668 M
+(   Copyright \(C\) The Internet Society \(2002\).  All Rights Reserved.) s
+5 646 M
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+5 635 M
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+%%EOF
diff --git a/lib/ssh/doc/standard/draft-ietf-secsh-filexfer-03.txt b/lib/ssh/doc/standard/draft-ietf-secsh-filexfer-03.txt
new file mode 100644
index 0000000000..83960ae976
--- /dev/null
+++ b/lib/ssh/doc/standard/draft-ietf-secsh-filexfer-03.txt
@@ -0,0 +1,1962 @@
+
+
+
+Secure Shell Working Group                                  J. Galbraith
+Internet-Draft                                          VanDyke Software
+Expires: April 16, 2003                                        T. Ylonen
+                                                             S. Lehtinen
+                                        SSH Communications Security Corp
+                                                        October 16, 2002
+
+
+                       SSH File Transfer Protocol
+                    draft-ietf-secsh-filexfer-03.txt
+
+Status of this Memo
+
+   This document is an Internet-Draft and is in full conformance with
+   all provisions of Section 10 of RFC2026.
+
+   Internet-Drafts are working documents of the Internet Engineering
+   Task Force (IETF), its areas, and its working groups.  Note that
+   other groups may also distribute working documents as Internet-
+   Drafts.
+
+   Internet-Drafts are draft documents valid for a maximum of six months
+   and may be updated, replaced, or obsoleted by other documents at any
+   time.  It is inappropriate to use Internet-Drafts as reference
+   material or to cite them other than as "work in progress."
+
+   The list of current Internet-Drafts can be accessed at http://
+   www.ietf.org/ietf/1id-abstracts.txt.
+
+   The list of Internet-Draft Shadow Directories can be accessed at
+   http://www.ietf.org/shadow.html.
+
+   This Internet-Draft will expire on April 16, 2003.
+
+Copyright Notice
+
+   Copyright (C) The Internet Society (2002).  All Rights Reserved.
+
+Abstract
+
+   The SSH File Transfer Protocol provides secure file transfer
+   functionality over any reliable data stream.  It is the standard file
+   transfer protocol for use with the SSH2 protocol.  This document
+   describes the file transfer protocol and its interface to the SSH2
+   protocol suite.
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                 [Page 1]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+Table of Contents
+
+   1.     Introduction . . . . . . . . . . . . . . . . . . . . . . .   3
+   2.     Use with the SSH Connection Protocol . . . . . . . . . . .   4
+   3.     General Packet Format  . . . . . . . . . . . . . . . . . .   5
+   4.     Protocol Initialization  . . . . . . . . . . . . . . . . .   7
+   4.1    Client Initialization  . . . . . . . . . . . . . . . . . .   7
+   4.2    Server Initialization  . . . . . . . . . . . . . . . . . .   7
+   4.3    Determining Server Newline Convention  . . . . . . . . . .   8
+   5.     File Attributes  . . . . . . . . . . . . . . . . . . . . .   9
+   5.1    Flags  . . . . . . . . . . . . . . . . . . . . . . . . . .   9
+   5.2    Type . . . . . . . . . . . . . . . . . . . . . . . . . . .  10
+   5.3    Size . . . . . . . . . . . . . . . . . . . . . . . . . . .  10
+   5.4    Owner and Group  . . . . . . . . . . . . . . . . . . . . .  10
+   5.5    Permissions  . . . . . . . . . . . . . . . . . . . . . . .  11
+   5.6    Times  . . . . . . . . . . . . . . . . . . . . . . . . . .  11
+   5.7    ACL  . . . . . . . . . . . . . . . . . . . . . . . . . . .  11
+   5.8    Extended attributes  . . . . . . . . . . . . . . . . . . .  12
+   6.     Requests From the Client to the Server . . . . . . . . . .  13
+   6.1    Request Synchronization and Reordering . . . . . . . . . .  13
+   6.2    File Names . . . . . . . . . . . . . . . . . . . . . . . .  14
+   6.3    Opening, Creating, and Closing Files . . . . . . . . . . .  14
+   6.4    Reading and Writing  . . . . . . . . . . . . . . . . . . .  17
+   6.5    Removing and Renaming Files  . . . . . . . . . . . . . . .  18
+   6.6    Creating and Deleting Directories  . . . . . . . . . . . .  19
+   6.7    Scanning Directories . . . . . . . . . . . . . . . . . . .  19
+   6.8    Retrieving File Attributes . . . . . . . . . . . . . . . .  20
+   6.9    Setting File Attributes  . . . . . . . . . . . . . . . . .  21
+   6.10   Dealing with Symbolic links  . . . . . . . . . . . . . . .  22
+   6.11   Canonicalizing the Server-Side Path Name . . . . . . . . .  23
+   6.11.1 Best practice for dealing with paths . . . . . . . . . . .  23
+   7.     Responses from the Server to the Client  . . . . . . . . .  24
+   8.     Vendor-Specific Extensions . . . . . . . . . . . . . . . .  28
+   9.     Security Considerations  . . . . . . . . . . . . . . . . .  29
+   10.    Changes from previous protocol versions  . . . . . . . . .  30
+   10.1   Changes between versions 4 and 3 . . . . . . . . . . . . .  30
+   10.2   Changes between versions 3 and 2 . . . . . . . . . . . . .  31
+   10.3   Changes between versions 2 and 1 . . . . . . . . . . . . .  31
+   10.4   Changes between versions 1 and 0 . . . . . . . . . . . . .  31
+   11.    Trademark Issues . . . . . . . . . . . . . . . . . . . . .  32
+          References . . . . . . . . . . . . . . . . . . . . . . . .  33
+          Authors' Addresses . . . . . . . . . . . . . . . . . . . .  33
+          Full Copyright Statement . . . . . . . . . . . . . . . . .  35
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                 [Page 2]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+1. Introduction
+
+   This protocol provides secure file transfer (and more generally file
+   system access) functionality over a reliable data stream, such as a
+   channel in the SSH2 protocol [5].
+
+   This protocol is designed so that it could be used to implement a
+   secure remote file system service, as well as a secure file transfer
+   service.
+
+   This protocol assumes that it runs over a secure channel, and that
+   the server has already authenticated the user at the client end, and
+   that the identity of the client user is externally available to the
+   server implementation.
+
+   In general, this protocol follows a simple request-response model.
+   Each request and response contains a sequence number and multiple
+   requests may be pending simultaneously.  There are a relatively large
+   number of different request messages, but a small number of possible
+   response messages.  Each request has one or more response messages
+   that may be returned in result (e.g., a read either returns data or
+   reports error status).
+
+   The packet format descriptions in this specification follow the
+   notation presented in the secsh architecture draft. [5]
+
+   Even though this protocol is described in the context of the SSH2
+   protocol, this protocol is general and independent of the rest of the
+   SSH2 protocol suite.  It could be used in a number of different
+   applications, such as secure file transfer over TLS RFC 2246 [1] and
+   transfer of management information in VPN applications.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                 [Page 3]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+2. Use with the SSH Connection Protocol
+
+   When used with the SSH2 Protocol suite, this protocol is intended to
+   be used from the SSH Connection Protocol [7] as a subsystem, as
+   described in section ``Starting a Shell or a Command''.  The
+   subsystem name used with this protocol is "sftp".
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                 [Page 4]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+3. General Packet Format
+
+   All packets transmitted over the secure connection are of the
+   following format:
+
+   	uint32             length
+   	byte               type
+   	byte[length - 1]   data payload
+
+   That is, they are just data preceded by 32-bit length and 8-bit type
+   fields.  The `length' is the length of the data area, and does not
+   include the `length' field itself.  The format and interpretation of
+   the data area depends on the packet type.
+
+   All packet descriptions below only specify the packet type and the
+   data that goes into the data field.  Thus, they should be prefixed by
+   the `length' and `type' fields.
+
+   The maximum size of a packet is in practice determined by the client
+   (the maximum size of read or write requests that it sends, plus a few
+   bytes of packet overhead).  All servers SHOULD support packets of at
+   least 34000 bytes (where the packet size refers to the full length,
+   including the header above).  This should allow for reads and writes
+   of at most 32768 bytes.
+
+   There is no limit on the number of outstanding (non-acknowledged)
+   requests that the client may send to the server.  In practice this is
+   limited by the buffering available on the data stream and the queuing
+   performed by the server.  If the server's queues are full, it should
+   not read any more data from the stream, and flow control will prevent
+   the client from sending more requests.  Note, however, that while
+   there is no restriction on the protocol level, the client's API may
+   provide a limit in order to prevent infinite queuing of outgoing
+   requests at the client.
+
+   The following values are defined for packet types.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                 [Page 5]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+   	#define SSH_FXP_INIT                1
+   	#define SSH_FXP_VERSION             2
+   	#define SSH_FXP_OPEN                3
+   	#define SSH_FXP_CLOSE               4
+   	#define SSH_FXP_READ                5
+   	#define SSH_FXP_WRITE               6
+   	#define SSH_FXP_LSTAT               7
+   	#define SSH_FXP_FSTAT               8
+   	#define SSH_FXP_SETSTAT             9
+   	#define SSH_FXP_FSETSTAT           10
+   	#define SSH_FXP_OPENDIR            11
+   	#define SSH_FXP_READDIR            12
+   	#define SSH_FXP_REMOVE             13
+   	#define SSH_FXP_MKDIR              14
+   	#define SSH_FXP_RMDIR              15
+   	#define SSH_FXP_REALPATH           16
+   	#define SSH_FXP_STAT               17
+   	#define SSH_FXP_RENAME             18
+   	#define SSH_FXP_READLINK           19
+   	#define SSH_FXP_SYMLINK            20
+
+   	#define SSH_FXP_STATUS            101
+   	#define SSH_FXP_HANDLE            102
+   	#define SSH_FXP_DATA              103
+   	#define SSH_FXP_NAME              104
+   	#define SSH_FXP_ATTRS             105
+
+   	#define SSH_FXP_EXTENDED          200
+   	#define SSH_FXP_EXTENDED_REPLY    201
+
+   	RESERVED_FOR_EXTENSIONS            210-255
+
+   Additional packet types should only be defined if the protocol
+   version number (see Section ``Protocol Initialization'') is
+   incremented, and their use MUST be negotiated using the version
+   number.  However, the SSH_FXP_EXTENDED and SSH_FXP_EXTENDED_REPLY
+   packets can be used to implement vendor-specific extensions.  See
+   Section ``Vendor-Specific-Extensions'' for more details.
+
+
+
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                 [Page 6]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+4. Protocol Initialization
+
+   When the file transfer protocol starts, the client first sends a
+   SSH_FXP_INIT (including its version number) packet to the server.
+   The server responds with a SSH_FXP_VERSION packet, supplying the
+   lowest of its own and the client's version number.  Both parties
+   should from then on adhere to particular version of the protocol.
+
+   The version number of the protocol specified in this document is 4.
+   The version number should be incremented for each incompatible
+   revision of this protocol.
+
+4.1 Client Initialization
+
+   The SSH_FXP_INIT packet (from client to server) has the following
+   data:
+
+   		uint32 version
+
+   Version 3 of this protocol allowed clients to include extensions in
+   the SSH_FXP_INIT packet; however, this can cause interoperability
+   problems with version 1 and version 2 servers because the client must
+   send this packet before knowing the servers version.
+
+   In this version of the protocol, clients MUST use the
+   SSH_FXP_EXTENDED packet to send extensions to the server after
+   version exchange has completed.  Clients MUST NOT include extensions
+   in the version packet.  This will prevent interoperability problems
+   with older servers
+
+4.2 Server Initialization
+
+   The SSH_FXP_VERSION packet (from server to client) has the following
+   data:
+
+   		uint32 version
+   		<extension data>
+
+   'version' is the lower of the protocol version supported by the
+   server and the version number received from the client.
+
+   The extension data may be empty, or may be a sequence of
+
+   		string extension_name
+   		string extension_data
+
+   pairs (both strings MUST always be present if one is, but the
+   `extension_data' string may be of zero length).  If present, these
+
+
+
+Galbraith, et al.        Expires April 16, 2003                 [Page 7]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+   strings indicate extensions to the baseline protocol.  The
+   `extension_name' field(s) identify the name of the extension.  The
+   name should be of the form "name@domain", where the domain is the DNS
+   domain name of the organization defining the extension.  Additional
+   names that are not of this format may be defined later by the IETF.
+   Implementations MUST silently ignore any extensions whose name they
+   do not recognize.
+
+4.3 Determining Server Newline Convention
+
+   In order to correctly process text files in a cross platform
+   compatible way, the newline convention must be converted from that of
+   the server to that of the client, or, during an upload, from that of
+   the client to that of the server.
+
+   Versions 3 and prior of this protocol made no provisions for
+   processing text files.  Many clients implemented some sort of
+   conversion algorithm, but without either a 'canonical' on the wire
+   format or knowledge of the servers newline convention, correct
+   conversion was not always possible.
+
+   Starting with Version 4, the SSH_FXF_TEXT file open flag (Section
+   6.3) makes it possible to request that the server translate a file to
+   a 'canonical' on the wire format.  This format uses \r\n as the line
+   separator.
+
+   Servers for systems using multiple newline characters (for example,
+   Mac OS X or VMS) or systems using counted records, MUST translate to
+   the canonical form.
+
+   However, to ease the burden of implementation on servers that use a
+   single, simple separator sequence, the following extension allows the
+   canonical format to be changed.
+
+   	string "newline"
+   	string new-canonical-separator (usually "\r" or "\n" or "\r\n")
+
+   All clients MUST support this extension.
+
+   When processing text files, clients SHOULD NOT translate any
+   character or sequence that is not an exact match of the servers
+   newline separator.
+
+   In particular, if the newline sequence being used is the canonical
+   "\r\n" sequence, a lone \r or a lone \n SHOULD be written through
+   without change.
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                 [Page 8]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+5. File Attributes
+
+   A new compound data type is defined for encoding file attributes.
+   The same encoding is used both when returning file attributes from
+   the server and when sending file attributes to the server.  When
+   sending it to the server, the flags field specifies which attributes
+   are included, and the server will use default values for the
+   remaining attributes (or will not modify the values of remaining
+   attributes).  When receiving attributes from the server, the flags
+   specify which attributes are included in the returned data.  The
+   server normally returns all attributes it knows about.
+
+   	uint32   flags
+   	byte     type           always present
+   	uint64   size           present only if flag SSH_FILEXFER_ATTR_SIZE
+   	string   owner          present only if flag SSH_FILEXFER_ATTR_OWNERGROUP
+   	string   group          present only if flag SSH_FILEXFER_ATTR_OWNERGROUP
+   	uint32   permissions    present only if flag SSH_FILEXFER_ATTR_PERMISSIONS
+   	uint32   atime          present only if flag SSH_FILEXFER_ATTR_ACCESSTIME
+   	uint32   createtime     present only if flag SSH_FILEXFER_ATTR_CREATETIME
+   	uint32   mtime          present only if flag SSH_FILEXFER_ATTR_MODIFYTIME
+   	string   acl            present only if flag SSH_FILEXFER_ATTR_ACL
+   	uint32   extended_count present only if flag SSH_FILEXFER_ATTR_EXTENDED
+   	string   extended_type
+   	string   extended_data
+   	...      more extended data (extended_type - extended_data pairs),
+   		   so that number of pairs equals extended_count
+
+
+5.1 Flags
+
+   The `flags' specify which of the fields are present.  Those fields
+   for which the corresponding flag is not set are not present (not
+   included in the packet).  New flags can only be added by incrementing
+   the protocol version number (or by using the extension mechanism
+   described below).
+
+   The flags bits are defined to have the following values:
+
+   	#define SSH_FILEXFER_ATTR_SIZE            0x00000001
+   	#define SSH_FILEXFER_ATTR_PERMISSIONS     0x00000004
+   	#define SSH_FILEXFER_ATTR_ACCESSTIME      0x00000008
+   	#define SSH_FILEXFER_ATTR_CREATETIME      0x00000010
+   	#define SSH_FILEXFER_ATTR_MODIFYTIME      0x00000020
+   	#define SSH_FILEXFER_ATTR_ACL             0x00000040
+   	#define SSH_FILEXFER_ATTR_OWNERGROUP      0x00000080
+   	#define SSH_FILEXFER_ATTR_EXTENDED        0x80000000
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                 [Page 9]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+   In previous versions of this protocol flags value 0x00000002 was
+   SSH_FILEXFER_ATTR_UIDGID.  This value is now unused, and OWNERGROUP
+   was given a new value in order to ease implementation burden.
+   0x00000002 MUST NOT appear in the mask.  Some future version of this
+   protocol may reuse flag 0x00000002.
+
+5.2 Type
+
+   The type field is always present.  The following types are defined:
+
+   	#define SSH_FILEXFER_TYPE_REGULAR          1
+   	#define SSH_FILEXFER_TYPE_DIRECTORY        2
+   	#define SSH_FILEXFER_TYPE_SYMLINK          3
+   	#define SSH_FILEXFER_TYPE_SPECIAL          4
+   	#define SSH_FILEXFER_TYPE_UNKNOWN          5
+
+   On a POSIX system, these values would be derived from the permission
+   field.
+
+5.3 Size
+
+   The `size' field specifies the size of the file on disk, in bytes.
+   If it is present during file creation, it should be considered a hint
+   as to the files eventual size.
+
+   Files opened with the SSH_FXF_TEXT flag may have a size that is
+   greater or less than the value of the size field.
+
+5.4 Owner and Group
+
+   The `owner' and `group' fields are represented as UTF-8 strings; this
+   is the form used by NFS v4.  See NFS version 4 Protocol.  [3] The
+   following text is selected quotations from section 5.6.
+
+   To avoid a representation that is tied to a particular underlying
+   implementation at the client or server, the use of UTF-8 strings has
+   been chosen.  The string should be of the form user@dns_domain".
+   This will allow for a client and server that do not use the same
+   local representation the ability to translate to a common syntax that
+   can be interpreted by both.  In the case where there is no
+   translation available to the client or server, the attribute value
+   must be constructed without the "@".  Therefore, the absence of the @
+   from the owner or owner_group attribute signifies that no translation
+   was available and the receiver of the attribute should not place any
+   special meaning with the attribute value.  Even though the attribute
+   value can not be translated, it may still be useful.  In the case of
+   a client, the attribute string may be used for local display of
+   ownership.
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 10]
+
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+
+
+5.5 Permissions
+
+   The `permissions' field contains a bit mask of file permissions as
+   defined by POSIX [1].
+
+5.6 Times
+
+   The 'atime', 'createtime', and 'mtime' contain the access, creation,
+   and modification times of the files, respectively.  They are
+   represented as seconds from Jan 1, 1970 in UTC.
+
+5.7 ACL
+
+   The 'ACL' field contains an ACL similar to that defined in section
+   5.9 of NFS version 4 Protocol [3].
+
+           uint32   ace-count
+
+           repeated ace-count time:
+   		uint32   ace-type
+   		uint32   ace-flag
+   		uint32   ace-mask
+   		string   who [UTF-8]
+
+   ace-type is one of the following four values (taken from NFS Version
+   4 Protocol [3]:
+
+   	const ACE4_ACCESS_ALLOWED_ACE_TYPE      = 0x00000000;
+   	const ACE4_ACCESS_DENIED_ACE_TYPE       = 0x00000001;
+   	const ACE4_SYSTEM_AUDIT_ACE_TYPE        = 0x00000002;
+   	const ACE4_SYSTEM_ALARM_ACE_TYPE        = 0x00000003;
+
+   ace-flag is a combination of the following flag values.  See NFS
+   Version 4 Protocol [3] section 5.9.2:
+
+   	const ACE4_FILE_INHERIT_ACE             = 0x00000001;
+   	const ACE4_DIRECTORY_INHERIT_ACE        = 0x00000002;
+   	const ACE4_NO_PROPAGATE_INHERIT_ACE     = 0x00000004;
+   	const ACE4_INHERIT_ONLY_ACE             = 0x00000008;
+   	const ACE4_SUCCESSFUL_ACCESS_ACE_FLAG   = 0x00000010;
+   	const ACE4_FAILED_ACCESS_ACE_FLAG       = 0x00000020;
+   	const ACE4_IDENTIFIER_GROUP             = 0x00000040;
+
+   ace-mask is any combination of the following flags (taken from NFS
+   Version 4 Protocol [3] section 5.9.3:
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 11]
+
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+
+
+   	const ACE4_READ_DATA            = 0x00000001;
+   	const ACE4_LIST_DIRECTORY       = 0x00000001;
+   	const ACE4_WRITE_DATA           = 0x00000002;
+   	const ACE4_ADD_FILE             = 0x00000002;
+   	const ACE4_APPEND_DATA          = 0x00000004;
+   	const ACE4_ADD_SUBDIRECTORY     = 0x00000004;
+   	const ACE4_READ_NAMED_ATTRS     = 0x00000008;
+   	const ACE4_WRITE_NAMED_ATTRS    = 0x00000010;
+   	const ACE4_EXECUTE              = 0x00000020;
+   	const ACE4_DELETE_CHILD         = 0x00000040;
+   	const ACE4_READ_ATTRIBUTES      = 0x00000080;
+   	const ACE4_WRITE_ATTRIBUTES     = 0x00000100;
+   	const ACE4_DELETE               = 0x00010000;
+   	const ACE4_READ_ACL             = 0x00020000;
+   	const ACE4_WRITE_ACL            = 0x00040000;
+   	const ACE4_WRITE_OWNER          = 0x00080000;
+   	const ACE4_SYNCHRONIZE          = 0x00100000;
+
+   who is a UTF-8 string of the form described in 'Owner and Group'
+   (Section 5.4)
+
+5.8 Extended attributes
+
+   The SSH_FILEXFER_ATTR_EXTENDED flag provides a general extension
+   mechanism for vendor-specific extensions.  If the flag is specified,
+   then the `extended_count' field is present.  It specifies the number
+   of extended_type-extended_data pairs that follow.  Each of these
+   pairs specifies an extended attribute.  For each of the attributes,
+   the extended_type field should be a string of the format
+   "name@domain", where "domain" is a valid, registered domain name and
+   "name" identifies the method.  The IETF may later standardize certain
+   names that deviate from this format (e.g., that do not contain the
+   "@" sign).  The interpretation of `extended_data' depends on the
+   type.  Implementations SHOULD ignore extended data fields that they
+   do not understand.
+
+   Additional fields can be added to the attributes by either defining
+   additional bits to the flags field to indicate their presence, or by
+   defining extended attributes for them.  The extended attributes
+   mechanism is recommended for most purposes; additional flags bits
+   should only be defined by an IETF standards action that also
+   increments the protocol version number.  The use of such new fields
+   MUST be negotiated by the version number in the protocol exchange.
+   It is a protocol error if a packet with unsupported protocol bits is
+   received.
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 12]
+
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+
+
+6. Requests From the Client to the Server
+
+   Requests from the client to the server represent the various file
+   system operations.  Each request begins with an `id' field, which is
+   a 32-bit identifier identifying the request (selected by the client).
+   The same identifier will be returned in the response to the request.
+   One possible implementation is a monotonically increasing request
+   sequence number (modulo 2^32).
+
+   Many operations in the protocol operate on open files.  The
+   SSH_FXP_OPEN request can return a file handle (which is an opaque
+   variable-length string) which may be used to access the file later
+   (e.g.  in a read operation).  The client MUST NOT send requests the
+   server with bogus or closed handles.  However, the server MUST
+   perform adequate checks on the handle in order to avoid security
+   risks due to fabricated handles.
+
+   This design allows either stateful and stateless server
+   implementation, as well as an implementation which caches state
+   between requests but may also flush it.  The contents of the file
+   handle string are entirely up to the server and its design.  The
+   client should not modify or attempt to interpret the file handle
+   strings.
+
+   The file handle strings MUST NOT be longer than 256 bytes.
+
+6.1 Request Synchronization and Reordering
+
+   The protocol and implementations MUST process requests relating to
+   the same file in the order in which they are received.  In other
+   words, if an application submits multiple requests to the server, the
+   results in the responses will be the same as if it had sent the
+   requests one at a time and waited for the response in each case.  For
+   example, the server may process non-overlapping read/write requests
+   to the same file in parallel, but overlapping reads and writes cannot
+   be reordered or parallelized.  However, there are no ordering
+   restrictions on the server for processing requests from two different
+   file transfer connections.  The server may interleave and parallelize
+   them at will.
+
+   There are no restrictions on the order in which responses to
+   outstanding requests are delivered to the client, except that the
+   server must ensure fairness in the sense that processing of no
+   request will be indefinitely delayed even if the client is sending
+   other requests so that there are multiple outstanding requests all
+   the time.
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 13]
+
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+
+
+6.2 File Names
+
+   This protocol represents file names as strings.  File names are
+   assumed to use the slash ('/') character as a directory separator.
+
+   File names starting with a slash are "absolute", and are relative to
+   the root of the file system.  Names starting with any other character
+   are relative to the user's default directory (home directory).  Note
+   that identifying the user is assumed to take place outside of this
+   protocol.
+
+   Servers SHOULD interpret a path name component ".." as referring to
+   the parent directory, and "." as referring to the current directory.
+   If the server implementation limits access to certain parts of the
+   file system, it must be extra careful in parsing file names when
+   enforcing such restrictions.  There have been numerous reported
+   security bugs where a ".." in a path name has allowed access outside
+   the intended area.
+
+   An empty path name is valid, and it refers to the user's default
+   directory (usually the user's home directory).
+
+   Otherwise, no syntax is defined for file names by this specification.
+   Clients should not make any other assumptions; however, they can
+   splice path name components returned by SSH_FXP_READDIR together
+   using a slash ('/') as the separator, and that will work as expected.
+
+   In order to comply with IETF Policy on Character Sets and Languages
+   [2], all filenames are to be encoded in UTF-8.  The shortest valid
+   UTF-8 encoding of the UNICODE data MUST be used.  The server is
+   responsible for converting the UNICODE data to whatever canonical
+   form it requires.
+
+   For example, if the server requires that precomposed characters
+   always be used, the server MUST NOT assume the filename as sent by
+   the client has this attribute, but must do this normalization itself.
+
+   It is understood that the lack of well-defined semantics for file
+   names may cause interoperability problems between clients and servers
+   using radically different operating systems.  However, this approach
+   is known to work acceptably with most systems, and alternative
+   approaches that e.g.  treat file names as sequences of structured
+   components are quite complicated.
+
+6.3 Opening, Creating, and Closing Files
+
+   Files are opened and created using the SSH_FXP_OPEN message, whose
+   data part is as follows:
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 14]
+
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+
+
+   	uint32        id
+   	string        filename [UTF-8]
+   	uint32        pflags
+   	ATTRS         attrs
+
+   The `id' field is the request identifier as for all requests.
+
+   The `filename' field specifies the file name.  See Section ``File
+   Names'' for more information.
+
+   The `pflags' field is a bitmask.  The following bits have been
+   defined.
+
+   	#define SSH_FXF_READ            0x00000001
+   	#define SSH_FXF_WRITE           0x00000002
+   	#define SSH_FXF_APPEND          0x00000004
+   	#define SSH_FXF_CREAT           0x00000008
+   	#define SSH_FXF_TRUNC           0x00000010
+   	#define SSH_FXF_EXCL            0x00000020
+   	#define SSH_FXF_TEXT            0x00000040
+
+   These have the following meanings:
+
+   SSH_FXF_READ
+      Open the file for reading.
+
+   SSH_FXF_WRITE
+      Open the file for writing.  If both this and SSH_FXF_READ are
+      specified, the file is opened for both reading and writing.
+
+   SSH_FXF_APPEND
+      Force all writes to append data at the end of the file.  The
+      offset parameter to write will be ignored.
+
+   SSH_FXF_CREAT
+      If this flag is specified, then a new file will be created if one
+      does not already exist (if O_TRUNC is specified, the new file will
+      be truncated to zero length if it previously exists).
+
+   SSH_FXF_TRUNC
+      Forces an existing file with the same name to be truncated to zero
+      length when creating a file by specifying SSH_FXF_CREAT.
+      SSH_FXF_CREAT MUST also be specified if this flag is used.
+
+   SSH_FXF_EXCL
+      Causes the request to fail if the named file already exists.
+      SSH_FXF_CREAT MUST also be specified if this flag is used.
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 15]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+   SSH_FXF_TEXT
+      Indicates that the server should treat the file as text and
+      convert it to the canonical newline convention in use.  (See
+      Determining Server Newline Convention. (Section 4.3)
+
+      When a file is opened with the FXF_TEXT flag, the offset field in
+      both the read and write function are ignored.
+
+      Servers MUST correctly process multiple parallel reads and writes
+      correctly in this mode.  Naturally, it is permissible for them to
+      do this by serializing the requests.  It would not be possible for
+      a client to reliably detect a server that does not implement
+      parallel writes in time to prevent damage.
+
+      Clients SHOULD use the SSH_FXF_APPEND flag to append data to a
+      text file rather then using write with a calculated offset.
+
+      To support seeks on text file the following SSH_FXP_EXTENDED
+      packet is defined.
+
+
+
+   	string "text-seek"
+   	string file-handle
+   	uint64 line-number
+
+      line-number is the index of the line number to seek to, where byte
+      0 in the file is line number 0, and the byte directly following
+      the first newline sequence in the file is line number 1 and so on.
+
+      The response to a "text-seek" request is an SSH_FXP_STATUS
+      message.
+
+      An attempt to seek past the end-of-file should result in a
+      SSH_FX_EOF status.
+
+      Servers SHOULD support at least one "text-seek" in order to
+      support resume.  However, a client MUST be prepared to receive
+      SSH_FX_OP_UNSUPPORTED when attempting a "text-seek" operation.
+      The client can then try a fall-back strategy, if it has one.
+
+      Clients MUST be prepared to handle SSH_FX_OP_UNSUPPORTED returned
+      for read or write operations that are not sequential.
+
+   The `attrs' field specifies the initial attributes for the file.
+   Default values will be used for those attributes that are not
+   specified.  See Section ``File Attributes'' for more information.
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 16]
+
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+
+
+   The response to this message will be either SSH_FXP_HANDLE (if the
+   operation is successful) or SSH_FXP_STATUS (if the operation fails).
+
+   A file is closed by using the SSH_FXP_CLOSE request.  Its data field
+   has the following format:
+
+   	uint32     id
+   	string     handle
+
+   where `id' is the request identifier, and `handle' is a handle
+   previously returned in the response to SSH_FXP_OPEN or
+   SSH_FXP_OPENDIR.  The handle becomes invalid immediately after this
+   request has been sent.
+
+   The response to this request will be a SSH_FXP_STATUS message.  One
+   should note that on some server platforms even a close can fail.
+   This can happen e.g.  if the server operating system caches writes,
+   and an error occurs while flushing cached writes during the close.
+
+6.4 Reading and Writing
+
+   Once a file has been opened, it can be read using the SSH_FXP_READ
+   message, which has the following format:
+
+   	uint32     id
+   	string     handle
+   	uint64     offset
+   	uint32     len
+
+   where `id' is the request identifier, `handle' is an open file handle
+   returned by SSH_FXP_OPEN, `offset' is the offset (in bytes) relative
+   to the beginning of the file from where to start reading, and `len'
+   is the maximum number of bytes to read.
+
+   In response to this request, the server will read as many bytes as it
+   can from the file (up to `len'), and return them in a SSH_FXP_DATA
+   message.  If an error occurs or EOF is encountered before reading any
+   data, the server will respond with SSH_FXP_STATUS.  For normal disk
+   files, it is guaranteed that this will read the specified number of
+   bytes, or up to end of file.  For e.g.  device files this may return
+   fewer bytes than requested.
+
+   Writing to a file is achieved using the SSH_FXP_WRITE message, which
+   has the following format:
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 17]
+
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+
+
+   	uint32     id
+   	string     handle
+   	uint64     offset
+   	string     data
+
+   where `id' is a request identifier, `handle' is a file handle
+   returned by SSH_FXP_OPEN, `offset' is the offset (in bytes) from the
+   beginning of the file where to start writing, and `data' is the data
+   to be written.
+
+   The write will extend the file if writing beyond the end of the file.
+   It is legal to write way beyond the end of the file; the semantics
+   are to write zeroes from the end of the file to the specified offset
+   and then the data.  On most operating systems, such writes do not
+   allocate disk space but instead leave "holes" in the file.
+
+   The server responds to a write request with a SSH_FXP_STATUS message.
+
+6.5 Removing and Renaming Files
+
+   Files can be removed using the SSH_FXP_REMOVE message.  It has the
+   following format:
+
+   	uint32     id
+   	string     filename [UTF-8]
+
+   where `id' is the request identifier and `filename' is the name of
+   the file to be removed.  See Section ``File Names'' for more
+   information.  This request cannot be used to remove directories.
+
+   The server will respond to this request with a SSH_FXP_STATUS
+   message.
+
+   Files (and directories) can be renamed using the SSH_FXP_RENAME
+   message.  Its data is as follows:
+
+   	uint32     id
+   	string     oldpath [UTF-8]
+   	string     newpath [UTF-8]
+
+   where `id' is the request identifier, `oldpath' is the name of an
+   existing file or directory, and `newpath' is the new name for the
+   file or directory.  It is an error if there already exists a file
+   with the name specified by newpath.  The server may also fail rename
+   requests in other situations, for example if `oldpath' and `newpath'
+   point to different file systems on the server.
+
+   The server will respond to this request with a SSH_FXP_STATUS
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 18]
+
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+
+
+   message.
+
+6.6 Creating and Deleting Directories
+
+   New directories can be created using the SSH_FXP_MKDIR request.  It
+   has the following format:
+
+   	uint32     id
+   	string     path [UTF-8]
+   	ATTRS      attrs
+
+   where `id' is the request identifier.
+
+   `path' specifies the directory to be created.  See Section ``File
+   Names'' for more information on file names.
+
+   `attrs' specifies the attributes that should be applied to it upon
+   creation.  Attributes are discussed in more detail in Section ``File
+   Attributes''.
+
+   The server will respond to this request with a SSH_FXP_STATUS
+   message.  If a file or directory with the specified path already
+   exists, an error will be returned.
+
+   Directories can be removed using the SSH_FXP_RMDIR request, which has
+   the following format:
+
+   	uint32     id
+   	string     path [UTF-8]
+
+   where `id' is the request identifier, and `path' specifies the
+   directory to be removed.  See Section ``File Names'' for more
+   information on file names.
+
+   The server responds to this request with a SSH_FXP_STATUS message.
+   Errors may be returned from this operation for various reasons,
+   including, but not limited to, the path does not exist, the path does
+   not refer to a directory object, the directory is not empty, or the
+   user has insufficient access or permission to perform the requested
+   operation.
+
+6.7 Scanning Directories
+
+   The files in a directory can be listed using the SSH_FXP_OPENDIR and
+   SSH_FXP_READDIR requests.  Each SSH_FXP_READDIR request returns one
+   or more file names with full file attributes for each file.  The
+   client should call SSH_FXP_READDIR repeatedly until it has found the
+   file it is looking for or until the server responds with a
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 19]
+
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+
+
+   SSH_FXP_STATUS message indicating an error (normally SSH_FX_EOF if
+   there are no more files in the directory).  The client should then
+   close the handle using the SSH_FXP_CLOSE request.
+
+   The SSH_FXP_OPENDIR opens a directory for reading.  It has the
+   following format:
+
+   	uint32     id
+   	string     path [UTF-8]
+
+   where `id' is the request identifier and `path' is the path name of
+   the directory to be listed (without any trailing slash).  See Section
+   ``File Names'' for more information on file names.  This will return
+   an error if the path does not specify a directory or if the directory
+   is not readable.  The server will respond to this request with either
+   a SSH_FXP_HANDLE or a SSH_FXP_STATUS message.
+
+   Once the directory has been successfully opened, files (and
+   directories) contained in it can be listed using SSH_FXP_READDIR
+   requests.  These are of the format
+
+   	uint32     id
+   	string     handle
+
+   where `id' is the request identifier, and `handle' is a handle
+   returned by SSH_FXP_OPENDIR.  (It is a protocol error to attempt to
+   use an ordinary file handle returned by SSH_FXP_OPEN.)
+
+   The server responds to this request with either a SSH_FXP_NAME or a
+   SSH_FXP_STATUS message.  One or more names may be returned at a time.
+   Full status information is returned for each name in order to speed
+   up typical directory listings.
+
+   If there are no more names available to be read, the server MUST
+   respond with a SSH_FXP_STATUS message with error code of SSH_FX_EOF.
+
+   When the client no longer wishes to read more names from the
+   directory, it SHOULD call SSH_FXP_CLOSE for the handle.  The handle
+   should be closed regardless of whether an error has occurred or not.
+
+6.8 Retrieving File Attributes
+
+   Very often, file attributes are automatically returned by
+   SSH_FXP_READDIR.  However, sometimes there is need to specifically
+   retrieve the attributes for a named file.  This can be done using the
+   SSH_FXP_STAT, SSH_FXP_LSTAT and SSH_FXP_FSTAT requests.
+
+   SSH_FXP_STAT and SSH_FXP_LSTAT only differ in that SSH_FXP_STAT
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 20]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+   follows symbolic links on the server, whereas SSH_FXP_LSTAT does not
+   follow symbolic links.  Both have the same format:
+
+   	uint32     id
+   	string     path [UTF-8]
+   	uint32     flags
+
+   where `id' is the request identifier, and `path' specifies the file
+   system object for which status is to be returned.  The server
+   responds to this request with either SSH_FXP_ATTRS or SSH_FXP_STATUS.
+
+   The flags field specify the attribute flags in which the client has
+   particular interest.  This is a hint to the server.  For example,
+   because retrieving owner / group and acl information can be an
+   expensive operation under some operating systems, the server may
+   choose not to retrieve this information unless the client expresses a
+   specific interest in it.
+
+   The client has no guarantee the server will provide all the fields
+   that it has expressed an interest in.
+
+   SSH_FXP_FSTAT differs from the others in that it returns status
+   information for an open file (identified by the file handle).  Its
+   format is as follows:
+
+   	uint32     id
+   	string     handle
+   	uint32     flags
+
+   where `id' is the request identifier and `handle' is a file handle
+   returned by SSH_FXP_OPEN.  The server responds to this request with
+   SSH_FXP_ATTRS or SSH_FXP_STATUS.
+
+6.9 Setting File Attributes
+
+   File attributes may be modified using the SSH_FXP_SETSTAT and
+   SSH_FXP_FSETSTAT requests.  These requests are used for operations
+   such as changing the ownership, permissions or access times, as well
+   as for truncating a file.
+
+   The SSH_FXP_SETSTAT request is of the following format:
+
+   	uint32     id
+   	string     path [UTF-8]
+   	ATTRS      attrs
+
+   where `id' is the request identifier, `path' specifies the file
+   system object (e.g.  file or directory) whose attributes are to be
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 21]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+   modified, and `attrs' specifies the modifications to be made to its
+   attributes.  Attributes are discussed in more detail in Section
+   ``File Attributes''.
+
+   An error will be returned if the specified file system object does
+   not exist or the user does not have sufficient rights to modify the
+   specified attributes.  The server responds to this request with a
+   SSH_FXP_STATUS message.
+
+   The SSH_FXP_FSETSTAT request modifies the attributes of a file which
+   is already open.  It has the following format:
+
+   	uint32     id
+   	string     handle
+   	ATTRS      attrs
+
+   where `id' is the request identifier, `handle' (MUST be returned by
+   SSH_FXP_OPEN) identifies the file whose attributes are to be
+   modified, and `attrs' specifies the modifications to be made to its
+   attributes.  Attributes are discussed in more detail in Section
+   ``File Attributes''.  The server will respond to this request with
+   SSH_FXP_STATUS.
+
+6.10 Dealing with Symbolic links
+
+   The SSH_FXP_READLINK request may be used to read the target of a
+   symbolic link.  It would have a data part as follows:
+
+   	uint32     id
+   	string     path [UTF-8]
+
+   where `id' is the request identifier and `path' specifies the path
+   name of the symlink to be read.
+
+   The server will respond with a SSH_FXP_NAME packet containing only
+   one name and a dummy attributes value.  The name in the returned
+   packet contains the target of the link.  If an error occurs, the
+   server may respond with SSH_FXP_STATUS.
+
+   The SSH_FXP_SYMLINK request will create a symbolic link on the
+   server.  It is of the following format
+
+   	uint32     id
+   	string     linkpath   [UTF-8]
+   	string     targetpath [UTF-8]
+
+   where `id' is the request identifier, `linkpath' specifies the path
+   name of the symlink to be created and `targetpath' specifies the
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 22]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+   target of the symlink.  The server shall respond with a
+   SSH_FXP_STATUS indicating either success (SSH_FX_OK) or an error
+   condition.
+
+6.11 Canonicalizing the Server-Side Path Name
+
+   The SSH_FXP_REALPATH request can be used to have the server
+   canonicalize any given path name to an absolute path.  This is useful
+   for converting path names containing ".." components or relative
+   pathnames without a leading slash into absolute paths.  The format of
+   the request is as follows:
+
+   	uint32     id
+   	string     path [UTF-8]
+
+   where `id' is the request identifier and `path' specifies the path
+   name to be canonicalized.  The server will respond with a
+   SSH_FXP_NAME packet containing the name in canonical form and a dummy
+   attributes value.  If an error occurs, the server may also respond
+   with SSH_FXP_STATUS.
+
+6.11.1 Best practice for dealing with paths
+
+   The client SHOULD treat the results of SSH_FXP_REALPATH as a
+   canonical absolute path, even if the path does not appear to be
+   absolute.  A client that use REALPATH(".") and treats the result as
+   absolute, even if there is no leading slash, will continue to
+   function correctly, even when talking to a Windows NT or VMS style
+   system, where absolute paths may not begin with a slash.
+
+   For example, if the client wishes to change directory up, and the
+   server has returned "c:/x/y/z" from REALPATH, the client SHOULD use
+   "c:/x/y/z/..".
+
+   As a second example, if the client wishes to open the file "x.txt" in
+   the current directory, and server has returned "dka100:/x/y/z" as the
+   canonical path of the directory, the client SHOULD open "dka100:/x/y/
+   z/x.txt"
+
+
+
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 23]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+7. Responses from the Server to the Client
+
+   The server responds to the client using one of a few response
+   packets.  All requests can return a SSH_FXP_STATUS response upon
+   failure.  When the operation is successful, any of the responses may
+   be returned (depending on the operation).  If no data needs to be
+   returned to the client, the SSH_FXP_STATUS response with SSH_FX_OK
+   status is appropriate.  Otherwise, the SSH_FXP_HANDLE message is used
+   to return a file handle (for SSH_FXP_OPEN and SSH_FXP_OPENDIR
+   requests), SSH_FXP_DATA is used to return data from SSH_FXP_READ,
+   SSH_FXP_NAME is used to return one or more file names from a
+   SSH_FXP_READDIR or SSH_FXP_REALPATH request, and SSH_FXP_ATTRS is
+   used to return file attributes from SSH_FXP_STAT, SSH_FXP_LSTAT, and
+   SSH_FXP_FSTAT requests.
+
+   Exactly one response will be returned for each request.  Each
+   response packet contains a request identifier which can be used to
+   match each response with the corresponding request.  Note that it is
+   legal to have several requests outstanding simultaneously, and the
+   server is allowed to send responses to them in a different order from
+   the order in which the requests were sent (the result of their
+   execution, however, is guaranteed to be as if they had been processed
+   one at a time in the order in which the requests were sent).
+
+   Response packets are of the same general format as request packets.
+   Each response packet begins with the request identifier.
+
+   The format of the data portion of the SSH_FXP_STATUS response is as
+   follows:
+
+   	uint32     id
+   	uint32     error/status code
+   	string     error message (ISO-10646 UTF-8 [RFC-2279])
+   	string     language tag (as defined in [RFC-1766])
+
+   where `id' is the request identifier, and `error/status code'
+   indicates the result of the requested operation.  The value SSH_FX_OK
+   indicates success, and all other values indicate failure.
+
+   Currently, the following values are defined (other values may be
+   defined by future versions of this protocol):
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 24]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+   	#define SSH_FX_OK                            0
+   	#define SSH_FX_EOF                           1
+   	#define SSH_FX_NO_SUCH_FILE                  2
+   	#define SSH_FX_PERMISSION_DENIED             3
+   	#define SSH_FX_FAILURE                       4
+   	#define SSH_FX_BAD_MESSAGE                   5
+   	#define SSH_FX_NO_CONNECTION                 6
+   	#define SSH_FX_CONNECTION_LOST               7
+   	#define SSH_FX_OP_UNSUPPORTED                8
+   	#define SSH_FX_INVALID_HANDLE                9
+   	#define SSH_FX_NO_SUCH_PATH                  10
+   	#define SSH_FX_FILE_ALREADY_EXISTS			 11
+   	#define SSH_FX_WRITE_PROTECT				 12
+
+   SSH_FX_OK
+      Indicates successful completion of the operation.
+
+   SSH_FX_EOF
+      indicates end-of-file condition; for SSH_FX_READ it means that no
+      more data is available in the file, and for SSH_FX_READDIR it
+      indicates that no more files are contained in the directory.
+
+   SSH_FX_NO_SUCH_FILE
+      is returned when a reference is made to a file which does not
+      exist.
+
+   SSH_FX_PERMISSION_DENIED
+      is returned when the authenticated user does not have sufficient
+      permissions to perform the operation.
+
+   SSH_FX_FAILURE
+      is a generic catch-all error message; it should be returned if an
+      error occurs for which there is no more specific error code
+      defined.
+
+   SSH_FX_BAD_MESSAGE
+      may be returned if a badly formatted packet or protocol
+      incompatibility is detected.
+
+   SSH_FX_NO_CONNECTION
+      is a pseudo-error which indicates that the client has no
+      connection to the server (it can only be generated locally by the
+      client, and MUST NOT be returned by servers).
+
+   SSH_FX_CONNECTION_LOST
+      is a pseudo-error which indicates that the connection to the
+      server has been lost (it can only be generated locally by the
+      client, and MUST NOT be returned by servers).
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 25]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+   SSH_FX_OP_UNSUPPORTED
+      indicates that an attempt was made to perform an operation which
+      is not supported for the server (it may be generated locally by
+      the client if e.g.  the version number exchange indicates that a
+      required feature is not supported by the server, or it may be
+      returned by the server if the server does not implement an
+      operation).
+
+   SSH_FX_INVALID_HANDLE
+      The handle value was invalid.
+
+   SSH_FX_NO_SUCH_PATH
+      The file path does not exist or is invalid.
+
+   SSH_FX_FILE_ALREADY_EXISTS
+      The file already exists.
+
+   SSH_FX_WRITE_PROTECT
+      The file is on read only media, or the media is write protected.
+
+   The SSH_FXP_HANDLE response has the following format:
+
+   	uint32     id
+   	string     handle
+
+   where `id' is the request identifier, and `handle' is an arbitrary
+   string that identifies an open file or directory on the server.  The
+   handle is opaque to the client; the client MUST NOT attempt to
+   interpret or modify it in any way.  The length of the handle string
+   MUST NOT exceed 256 data bytes.
+
+   The SSH_FXP_DATA response has the following format:
+
+   	uint32     id
+   	string     data
+
+   where `id' is the request identifier, and `data' is an arbitrary byte
+   string containing the requested data.  The data string may be at most
+   the number of bytes requested in a SSH_FXP_READ request, but may also
+   be shorter if end of file is reached or if the read is from something
+   other than a regular file.
+
+   The SSH_FXP_NAME response has the following format:
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 26]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+   	uint32     id
+   	uint32     count
+   	repeats count times:
+   		string     filename [UTF-8]
+   		ATTRS      attrs
+
+   where `id' is the request identifier, `count' is the number of names
+   returned in this response, and the remaining fields repeat `count'
+   times (so that all three fields are first included for the first
+   file, then for the second file, etc).  In the repeated part,
+   `filename' is a file name being returned (for SSH_FXP_READDIR, it
+   will be a relative name within the directory, without any path
+   components; for SSH_FXP_REALPATH it will be an absolute path name),
+   and `attrs' is the attributes of the file as described in Section
+   ``File Attributes''.
+
+   The SSH_FXP_ATTRS response has the following format:
+
+   	uint32     id
+   	ATTRS      attrs
+
+   where `id' is the request identifier, and `attrs' is the returned
+   file attributes as described in Section ``File Attributes''.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 27]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+8. Vendor-Specific Extensions
+
+   The SSH_FXP_EXTENDED request provides a generic extension mechanism
+   for adding vendor-specific commands.  The request has the following
+   format:
+
+   	uint32     id
+   	string     extended-request
+   	... any request-specific data ...
+
+   where `id' is the request identifier, and `extended-request' is a
+   string of the format "name@domain", where domain is an internet
+   domain name of the vendor defining the request.  The rest of the
+   request is completely vendor-specific, and servers should only
+   attempt to interpret it if they recognize the `extended-request'
+   name.
+
+   The server may respond to such requests using any of the response
+   packets defined in Section ``Responses from the Server to the
+   Client''.  Additionally, the server may also respond with a
+   SSH_FXP_EXTENDED_REPLY packet, as defined below.  If the server does
+   not recognize the `extended-request' name, then the server MUST
+   respond with SSH_FXP_STATUS with error/status set to
+   SSH_FX_OP_UNSUPPORTED.
+
+   The SSH_FXP_EXTENDED_REPLY packet can be used to carry arbitrary
+   extension-specific data from the server to the client.  It is of the
+   following format:
+
+   	uint32     id
+   	... any request-specific data ...
+
+   There is a range of packet types reserved for use by extensions.  In
+   order to avoid collision, extensions that turn on the use of
+   additional packet types should determine those numbers dynamically.
+
+   The suggested way of doing this is have an extension request from the
+   client to the server that enables the extension; the extension
+   response from the server to the client would specify the actual type
+   values to use, in additional to any other data.
+
+   Extension authors should be mindful of the limited range of packet
+   types available (there are only 45 values available) and avoid
+   requiring a new packet type where possible.
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 28]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+9. Security Considerations
+
+   This protocol assumes that it is run over a secure channel and that
+   the endpoints of the channel have been authenticated.  Thus, this
+   protocol assumes that it is externally protected from network-level
+   attacks.
+
+   This protocol provides file system access to arbitrary files on the
+   server (only constrained by the server implementation).  It is the
+   responsibility of the server implementation to enforce any access
+   controls that may be required to limit the access allowed for any
+   particular user (the user being authenticated externally to this
+   protocol, typically using the SSH User Authentication Protocol [8].
+
+   Care must be taken in the server implementation to check the validity
+   of received file handle strings.  The server should not rely on them
+   directly; it MUST check the validity of each handle before relying on
+   it.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 29]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+10. Changes from previous protocol versions
+
+   The SSH File Transfer Protocol has changed over time, before it's
+   standardization.  The following is a description of the incompatible
+   changes between different versions.
+
+10.1 Changes between versions 4 and 3
+
+   Many of the changes between version 4 and version 3 are to the
+   attribute structure to make it more flexible for non-unix platforms.
+
+   o  Make all filenames UTF-8.
+
+   o  Added 'newline' extension.
+
+   o  Made file attribute owner and group strings so they can actually
+      be used on disparate systems.
+
+   o  Added createtime field, and added separate flags for atime,
+      createtime, and mtime so they can be set separately.
+
+   o  Split the file type out of the permissions field and into it's own
+      field (which is always present.)
+
+   o  Added acl attribute.
+
+   o  Added SSH_FXF_TEXT file open flag.
+
+   o  Added flags field to the get stat commands so that the client can
+      specifically request information the server might not normally
+      included for performance reasons.
+
+   o  Removed the long filename from the names structure-- it can now be
+      built from information available in the attrs structure.
+
+   o  Added reserved range of packet numbers for extensions.
+
+   o  Added several additional error codes.
+
+   o  Change the way version negotiate works slightly.  Previously, if
+      the client version were higher than the server version, the server
+      was supposed to 'echo back' the clients version.  The server now
+      sends it's own version and the lower of the two is considered to
+      be the one in use.
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 30]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+10.2 Changes between versions 3 and 2
+
+   o  The SSH_FXP_READLINK and SSH_FXP_SYMLINK messages were added.
+
+   o  The SSH_FXP_EXTENDED and SSH_FXP_EXTENDED_REPLY messages were
+      added.
+
+   o  The SSH_FXP_STATUS message was changed to include fields `error
+      message' and `language tag'.
+
+
+10.3 Changes between versions 2 and 1
+
+   o  The SSH_FXP_RENAME message was added.
+
+
+10.4 Changes between versions 1 and 0
+
+   o  Implementation changes, no actual protocol changes.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 31]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+11. Trademark Issues
+
+   "ssh" is a registered trademark of SSH Communications Security Corp
+   in the United States and/or other countries.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 32]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+References
+
+   [1]  Dierks, T., Allen, C., Treese, W., Karlton, P., Freier, A. and
+        P. Kocher, "The TLS Protocol Version 1.0", RFC 2246, January
+        1999.
+
+   [2]  Alvestrand, H., "IETF Policy on Character Sets and Languages",
+        BCP 18, RFC 2277, January 1998.
+
+   [3]  Shepler, S., Callaghan, B., Robinson, D., Thurlow, R., Beame,
+        C., Eisler, M. and D. Noveck, "NFS version 4 Protocol", RFC
+        3010, December 2000.
+
+   [4]  Institute of Electrical and Electronics Engineers, "Information
+        Technology - Portable Operating System Interface (POSIX) - Part
+        1: System Application Program Interface (API) [C Language]",
+        IEEE Standard 1003.2, 1996.
+
+   [5]  Rinne, T., Ylonen, T., Kivinen, T., Saarinen, M. and S.
+        Lehtinen, "SSH Protocol Architecture", draft-ietf-secsh-
+        architecture-13 (work in progress), September 2002.
+
+   [6]  Rinne, T., Ylonen, T., Kivinen, T., Saarinen, M. and S.
+        Lehtinen, "SSH Protocol Transport Protocol", draft-ietf-secsh-
+        transport-15 (work in progress), September 2002.
+
+   [7]  Rinne, T., Ylonen, T., Kivinen, T., Saarinen, M. and S.
+        Lehtinen, "SSH Connection Protocol", draft-ietf-secsh-connect-16
+        (work in progress), September 2002.
+
+   [8]  Rinne, T., Ylonen, T., Kivinen, T., Saarinen, M. and S.
+        Lehtinen, "SSH Authentication Protocol", draft-ietf-secsh-
+        userauth-16 (work in progress), September 2002.
+
+
+Authors' Addresses
+
+   Joseph Galbraith
+   VanDyke Software
+   4848 Tramway Ridge Blvd
+   Suite 101
+   Albuquerque, NM  87111
+   US
+
+   Phone: +1 505 332 5700
+   EMail: [email protected]
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 33]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+   Tatu Ylonen
+   SSH Communications Security Corp
+   Fredrikinkatu 42
+   HELSINKI  FIN-00100
+   Finland
+
+   EMail: [email protected]
+
+
+   Sami Lehtinen
+   SSH Communications Security Corp
+   Fredrikinkatu 42
+   HELSINKI  FIN-00100
+   Finland
+
+   EMail: [email protected]
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 34]
+
+Internet-Draft         SSH File Transfer Protocol           October 2002
+
+
+Full Copyright Statement
+
+   Copyright (C) The Internet Society (2002).  All Rights Reserved.
+
+   This document and translations of it may be copied and furnished to
+   others, and derivative works that comment on or otherwise explain it
+   or assist in its implementation may be prepared, copied, published
+   and distributed, in whole or in part, without restriction of any
+   kind, provided that the above copyright notice and this paragraph are
+   included on all such copies and derivative works.  However, this
+   document itself may not be modified in any way, such as by removing
+   the copyright notice or references to the Internet Society or other
+   Internet organizations, except as needed for the purpose of
+   developing Internet standards in which case the procedures for
+   copyrights defined in the Internet Standards process must be
+   followed, or as required to translate it into languages other than
+   English.
+
+   The limited permissions granted above are perpetual and will not be
+   revoked by the Internet Society or its successors or assigns.
+
+   This document and the information contained herein is provided on an
+   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
+   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
+   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
+   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
+   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+
+Acknowledgement
+
+   Funding for the RFC Editor function is currently provided by the
+   Internet Society.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires April 16, 2003                [Page 35]
+
+
diff --git a/lib/ssh/doc/standard/draft-ietf-secsh-filexfer-04.txt b/lib/ssh/doc/standard/draft-ietf-secsh-filexfer-04.txt
new file mode 100644
index 0000000000..9f51883cd2
--- /dev/null
+++ b/lib/ssh/doc/standard/draft-ietf-secsh-filexfer-04.txt
@@ -0,0 +1,2130 @@
+
+
+
+Secure Shell Working Group                                  J. Galbraith
+Internet-Draft                                          VanDyke Software
+Expires: June 18, 2003                                         T. Ylonen
+                                                             S. Lehtinen
+                                        SSH Communications Security Corp
+                                                       December 18, 2002
+
+
+                       SSH File Transfer Protocol
+                    draft-ietf-secsh-filexfer-04.txt
+
+Status of this Memo
+
+   This document is an Internet-Draft and is in full conformance with
+   all provisions of Section 10 of RFC2026.
+
+   Internet-Drafts are working documents of the Internet Engineering
+   Task Force (IETF), its areas, and its working groups.  Note that
+   other groups may also distribute working documents as
+   Internet-Drafts.
+
+   Internet-Drafts are draft documents valid for a maximum of six months
+   and may be updated, replaced, or obsoleted by other documents at any
+   time.  It is inappropriate to use Internet-Drafts as reference
+   material or to cite them other than as "work in progress."
+
+   The list of current Internet-Drafts can be accessed at http://
+   www.ietf.org/ietf/1id-abstracts.txt.
+
+   The list of Internet-Draft Shadow Directories can be accessed at
+   http://www.ietf.org/shadow.html.
+
+   This Internet-Draft will expire on June 18, 2003.
+
+Copyright Notice
+
+   Copyright (C) The Internet Society (2002).  All Rights Reserved.
+
+Abstract
+
+   The SSH File Transfer Protocol provides secure file transfer
+   functionality over any reliable data stream.  It is the standard file
+   transfer protocol for use with the SSH2 protocol.  This document
+   describes the file transfer protocol and its interface to the SSH2
+   protocol suite.
+
+
+
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                  [Page 1]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+Table of Contents
+
+   1.     Introduction . . . . . . . . . . . . . . . . . . . . . . .   3
+   2.     Use with the SSH Connection Protocol . . . . . . . . . . .   4
+   3.     General Packet Format  . . . . . . . . . . . . . . . . . .   5
+   3.1    The use of stderr in the server  . . . . . . . . . . . . .   6
+   4.     Protocol Initialization  . . . . . . . . . . . . . . . . .   8
+   4.1    Client Initialization  . . . . . . . . . . . . . . . . . .   8
+   4.2    Server Initialization  . . . . . . . . . . . . . . . . . .   8
+   4.3    Determining Server Newline Convention  . . . . . . . . . .   9
+   5.     File Attributes  . . . . . . . . . . . . . . . . . . . . .  10
+   5.1    Flags  . . . . . . . . . . . . . . . . . . . . . . . . . .  10
+   5.2    Type . . . . . . . . . . . . . . . . . . . . . . . . . . .  11
+   5.3    Size . . . . . . . . . . . . . . . . . . . . . . . . . . .  11
+   5.4    Owner and Group  . . . . . . . . . . . . . . . . . . . . .  11
+   5.5    Permissions  . . . . . . . . . . . . . . . . . . . . . . .  12
+   5.6    Times  . . . . . . . . . . . . . . . . . . . . . . . . . .  12
+   5.7    ACL  . . . . . . . . . . . . . . . . . . . . . . . . . . .  12
+   5.8    Extended attributes  . . . . . . . . . . . . . . . . . . .  14
+   6.     Requests From the Client to the Server . . . . . . . . . .  15
+   6.1    Request Synchronization and Reordering . . . . . . . . . .  15
+   6.2    File Names . . . . . . . . . . . . . . . . . . . . . . . .  16
+   6.3    Opening, Creating, and Closing Files . . . . . . . . . . .  16
+   6.4    Reading and Writing  . . . . . . . . . . . . . . . . . . .  19
+   6.5    Removing and Renaming Files  . . . . . . . . . . . . . . .  20
+   6.6    Creating and Deleting Directories  . . . . . . . . . . . .  21
+   6.7    Scanning Directories . . . . . . . . . . . . . . . . . . .  21
+   6.8    Retrieving File Attributes . . . . . . . . . . . . . . . .  22
+   6.9    Setting File Attributes  . . . . . . . . . . . . . . . . .  23
+   6.10   Dealing with Symbolic links  . . . . . . . . . . . . . . .  24
+   6.11   Canonicalizing the Server-Side Path Name . . . . . . . . .  25
+   6.11.1 Best practice for dealing with paths . . . . . . . . . . .  25
+   7.     Responses from the Server to the Client  . . . . . . . . .  26
+   8.     Vendor-Specific Extensions . . . . . . . . . . . . . . . .  30
+   9.     Security Considerations  . . . . . . . . . . . . . . . . .  31
+   10.    Changes from previous protocol versions  . . . . . . . . .  32
+   10.1   Changes between versions 4 and 3 . . . . . . . . . . . . .  32
+   10.2   Changes between versions 3 and 2 . . . . . . . . . . . . .  33
+   10.3   Changes between versions 2 and 1 . . . . . . . . . . . . .  33
+   10.4   Changes between versions 1 and 0 . . . . . . . . . . . . .  33
+   11.    Trademark Issues . . . . . . . . . . . . . . . . . . . . .  34
+          References . . . . . . . . . . . . . . . . . . . . . . . .  35
+          Authors' Addresses . . . . . . . . . . . . . . . . . . . .  35
+          Intellectual Property and Copyright Statements . . . . . .  37
+
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+Galbraith, et al.        Expires June 18, 2003                  [Page 2]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+1. Introduction
+
+   This protocol provides secure file transfer (and more generally file
+   system access) functionality over a reliable data stream, such as a
+   channel in the SSH2 protocol [5].
+
+   This protocol is designed so that it could be used to implement a
+   secure remote file system service, as well as a secure file transfer
+   service.
+
+   This protocol assumes that it runs over a secure channel, and that
+   the server has already authenticated the user at the client end, and
+   that the identity of the client user is externally available to the
+   server implementation.
+
+   In general, this protocol follows a simple request-response model.
+   Each request and response contains a sequence number and multiple
+   requests may be pending simultaneously.  There are a relatively large
+   number of different request messages, but a small number of possible
+   response messages.  Each request has one or more response messages
+   that may be returned in result (e.g., a read either returns data or
+   reports error status).
+
+   The packet format descriptions in this specification follow the
+   notation presented in the secsh architecture draft. [5]
+
+   Even though this protocol is described in the context of the SSH2
+   protocol, this protocol is general and independent of the rest of the
+   SSH2 protocol suite.  It could be used in a number of different
+   applications, such as secure file transfer over TLS RFC 2246 [1] and
+   transfer of management information in VPN applications.
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+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+2. Use with the SSH Connection Protocol
+
+   When used with the SSH2 Protocol suite, this protocol is intended to
+   be used from the SSH Connection Protocol [7] as a subsystem, as
+   described in section ``Starting a Shell or a Command''.  The
+   subsystem name used with this protocol is "sftp".
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+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+3. General Packet Format
+
+   All packets transmitted over the secure connection are of the
+   following format:
+
+   	uint32             length
+   	byte               type
+   	byte[length - 1]   data payload
+
+   That is, they are just data preceded by 32-bit length and 8-bit type
+   fields.  The `length' is the length of the data area, and does not
+   include the `length' field itself.  The format and interpretation of
+   the data area depends on the packet type.
+
+   All packet descriptions below only specify the packet type and the
+   data that goes into the data field.  Thus, they should be prefixed by
+   the `length' and `type' fields.
+
+   The maximum size of a packet is in practice determined by the client
+   (the maximum size of read or write requests that it sends, plus a few
+   bytes of packet overhead).  All servers SHOULD support packets of at
+   least 34000 bytes (where the packet size refers to the full length,
+   including the header above).  This should allow for reads and writes
+   of at most 32768 bytes.
+
+   There is no limit on the number of outstanding (non-acknowledged)
+   requests that the client may send to the server.  In practice this is
+   limited by the buffering available on the data stream and the queuing
+   performed by the server.  If the server's queues are full, it should
+   not read any more data from the stream, and flow control will prevent
+   the client from sending more requests.  Note, however, that while
+   there is no restriction on the protocol level, the client's API may
+   provide a limit in order to prevent infinite queuing of outgoing
+   requests at the client.
+
+   The following values are defined for packet types.
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+Galbraith, et al.        Expires June 18, 2003                  [Page 5]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+   	#define SSH_FXP_INIT                1
+   	#define SSH_FXP_VERSION             2
+   	#define SSH_FXP_OPEN                3
+   	#define SSH_FXP_CLOSE               4
+   	#define SSH_FXP_READ                5
+   	#define SSH_FXP_WRITE               6
+   	#define SSH_FXP_LSTAT               7
+   	#define SSH_FXP_FSTAT               8
+   	#define SSH_FXP_SETSTAT             9
+   	#define SSH_FXP_FSETSTAT           10
+   	#define SSH_FXP_OPENDIR            11
+   	#define SSH_FXP_READDIR            12
+   	#define SSH_FXP_REMOVE             13
+   	#define SSH_FXP_MKDIR              14
+   	#define SSH_FXP_RMDIR              15
+   	#define SSH_FXP_REALPATH           16
+   	#define SSH_FXP_STAT               17
+   	#define SSH_FXP_RENAME             18
+   	#define SSH_FXP_READLINK           19
+   	#define SSH_FXP_SYMLINK            20
+
+   	#define SSH_FXP_STATUS            101
+   	#define SSH_FXP_HANDLE            102
+   	#define SSH_FXP_DATA              103
+   	#define SSH_FXP_NAME              104
+   	#define SSH_FXP_ATTRS             105
+
+   	#define SSH_FXP_EXTENDED          200
+   	#define SSH_FXP_EXTENDED_REPLY    201
+
+   	RESERVED_FOR_EXTENSIONS            210-255
+
+   Additional packet types should only be defined if the protocol
+   version number (see Section ``Protocol Initialization'') is
+   incremented, and their use MUST be negotiated using the version
+   number.  However, the SSH_FXP_EXTENDED and SSH_FXP_EXTENDED_REPLY
+   packets can be used to implement vendor-specific extensions.  See
+   Section ``Vendor-Specific-Extensions'' for more details.
+
+3.1 The use of stderr in the server
+
+   Packets are sent and received on stdout and stdin.  Data sent on
+   stderr by the server SHOULD be considered debug or supplemental error
+   information, and MAY be displayed to the user.
+
+   For example, during initialization, there is no client request
+   active, so errors or warning information cannot be sent to the client
+   as part of the SFTP protocol at this early stage.  However, the
+
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+
+Galbraith, et al.        Expires June 18, 2003                  [Page 6]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
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+   errors or warnings MAY be sent as stderr text.
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+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+4. Protocol Initialization
+
+   When the file transfer protocol starts, the client first sends a
+   SSH_FXP_INIT (including its version number) packet to the server.
+   The server responds with a SSH_FXP_VERSION packet, supplying the
+   lowest of its own and the client's version number.  Both parties
+   should from then on adhere to particular version of the protocol.
+
+   The version number of the protocol specified in this document is 4.
+   The version number should be incremented for each incompatible
+   revision of this protocol.
+
+4.1 Client Initialization
+
+   The SSH_FXP_INIT packet (from client to server) has the following
+   data:
+
+   		uint32 version
+
+   Version 3 of this protocol allowed clients to include extensions in
+   the SSH_FXP_INIT packet; however, this can cause interoperability
+   problems with version 1 and version 2 servers because the client must
+   send this packet before knowing the servers version.
+
+   In this version of the protocol, clients MUST use the
+   SSH_FXP_EXTENDED packet to send extensions to the server after
+   version exchange has completed.  Clients MUST NOT include extensions
+   in the version packet.  This will prevent interoperability problems
+   with older servers
+
+4.2 Server Initialization
+
+   The SSH_FXP_VERSION packet (from server to client) has the following
+   data:
+
+   		uint32 version
+   		<extension data>
+
+   'version' is the lower of the protocol version supported by the
+   server and the version number received from the client.
+
+   The extension data may be empty, or may be a sequence of
+
+   		string extension_name
+   		string extension_data
+
+   pairs (both strings MUST always be present if one is, but the
+   `extension_data' string may be of zero length).  If present, these
+
+
+
+Galbraith, et al.        Expires June 18, 2003                  [Page 8]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+   strings indicate extensions to the baseline protocol.  The
+   `extension_name' field(s) identify the name of the extension.  The
+   name should be of the form "name@domain", where the domain is the DNS
+   domain name of the organization defining the extension.  Additional
+   names that are not of this format may be defined later by the IETF.
+   Implementations MUST silently ignore any extensions whose name they
+   do not recognize.
+
+4.3 Determining Server Newline Convention
+
+   In order to correctly process text files in a cross platform
+   compatible way, the newline convention must be converted from that of
+   the server to that of the client, or, during an upload, from that of
+   the client to that of the server.
+
+   Versions 3 and prior of this protocol made no provisions for
+   processing text files.  Many clients implemented some sort of
+   conversion algorithm, but without either a 'canonical' on the wire
+   format or knowledge of the servers newline convention, correct
+   conversion was not always possible.
+
+   Starting with Version 4, the SSH_FXF_TEXT file open flag (Section
+   6.3) makes it possible to request that the server translate a file to
+   a 'canonical' on the wire format.  This format uses \r\n as the line
+   separator.
+
+   Servers for systems using multiple newline characters (for example,
+   Mac OS X or VMS) or systems using counted records, MUST translate to
+   the canonical form.
+
+   However, to ease the burden of implementation on servers that use a
+   single, simple separator sequence, the following extension allows the
+   canonical format to be changed.
+
+   	string "newline"
+   	string new-canonical-separator (usually "\r" or "\n" or "\r\n")
+
+   All clients MUST support this extension.
+
+   When processing text files, clients SHOULD NOT translate any
+   character or sequence that is not an exact match of the servers
+   newline separator.
+
+   In particular, if the newline sequence being used is the canonical
+   "\r\n" sequence, a lone \r or a lone \n SHOULD be written through
+   without change.
+
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+Galbraith, et al.        Expires June 18, 2003                  [Page 9]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+5. File Attributes
+
+   A new compound data type is defined for encoding file attributes.
+   The same encoding is used both when returning file attributes from
+   the server and when sending file attributes to the server.  When
+   sending it to the server, the flags field specifies which attributes
+   are included, and the server will use default values for the
+   remaining attributes (or will not modify the values of remaining
+   attributes).  When receiving attributes from the server, the flags
+   specify which attributes are included in the returned data.  The
+   server normally returns all attributes it knows about.
+
+   	uint32   flags
+   	byte     type                 always present
+   	uint64   size                 present only if flag SIZE
+   	string   owner                present only if flag OWNERGROUP
+   	string   group                present only if flag OWNERGROUP
+   	uint32   permissions          present only if flag PERMISSIONS
+   	uint64   atime                present only if flag ACCESSTIME
+   	uint32   atime_nseconds       present only if flag SUBSECOND_TIMES
+   	uint64   createtime           present only if flag CREATETIME
+   	uint32   createtime_nseconds  present only if flag SUBSECOND_TIMES
+   	uint64   mtime                present only if flag MODIFYTIME
+   	uint32   mtime_nseconds       present only if flag SUBSECOND_TIMES
+   	string   acl                  present only if flag ACL
+   	uint32   extended_count       present only if flag EXTENDED
+   	string   extended_type
+   	string   extended_data
+   	...      more extended data (extended_type - extended_data pairs),
+   		   so that number of pairs equals extended_count
+
+
+5.1 Flags
+
+   The `flags' specify which of the fields are present.  Those fields
+   for which the corresponding flag is not set are not present (not
+   included in the packet).  New flags can only be added by incrementing
+   the protocol version number (or by using the extension mechanism
+   described below).
+
+   The flags bits are defined to have the following values:
+
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+Galbraith, et al.        Expires June 18, 2003                 [Page 10]
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+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+   	#define SSH_FILEXFER_ATTR_SIZE              0x00000001
+   	#define SSH_FILEXFER_ATTR_PERMISSIONS       0x00000040
+   	#define SSH_FILEXFER_ATTR_ACCESSTIME        0x00000008
+   	#define SSH_FILEXFER_ATTR_CREATETIME        0x00000010
+   	#define SSH_FILEXFER_ATTR_MODIFYTIME        0x00000020
+   	#define SSH_FILEXFER_ATTR_ACL               0x00000040
+   	#define SSH_FILEXFER_ATTR_OWNERGROUP        0x00000080
+   	#define SSH_FILEXFER_ATTR_SUBSECOND_TIMES	0x00000100
+   	#define SSH_FILEXFER_ATTR_EXTENDED          0x80000000
+
+   In previous versions of this protocol flags value 0x00000002 was
+   SSH_FILEXFER_ATTR_UIDGID.  This value is now unused, and OWNERGROUP
+   was given a new value in order to ease implementation burden.
+   0x00000002 MUST NOT appear in the mask.  Some future version of this
+   protocol may reuse flag 0x00000002.
+
+5.2 Type
+
+   The type field is always present.  The following types are defined:
+
+   	#define SSH_FILEXFER_TYPE_REGULAR          1
+   	#define SSH_FILEXFER_TYPE_DIRECTORY        2
+   	#define SSH_FILEXFER_TYPE_SYMLINK          3
+   	#define SSH_FILEXFER_TYPE_SPECIAL          4
+   	#define SSH_FILEXFER_TYPE_UNKNOWN          5
+
+   On a POSIX system, these values would be derived from the permission
+   field.
+
+5.3 Size
+
+   The `size' field specifies the size of the file on disk, in bytes.
+   If it is present during file creation, it should be considered a hint
+   as to the files eventual size.
+
+   Files opened with the SSH_FXF_TEXT flag may have a size that is
+   greater or less than the value of the size field.
+
+5.4 Owner and Group
+
+   The `owner' and `group' fields are represented as UTF-8 strings; this
+   is the form used by NFS v4.  See NFS version 4 Protocol.  [3] The
+   following text is selected quotations from section 5.6.
+
+   To avoid a representation that is tied to a particular underlying
+   implementation at the client or server, the use of UTF-8 strings has
+   been chosen.  The string should be of the form user@dns_domain".
+   This will allow for a client and server that do not use the same
+
+
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+   local representation the ability to translate to a common syntax that
+   can be interpreted by both.  In the case where there is no
+   translation available to the client or server, the attribute value
+   must be constructed without the "@".  Therefore, the absence of the @
+   from the owner or owner_group attribute signifies that no translation
+   was available and the receiver of the attribute should not place any
+   special meaning with the attribute value.  Even though the attribute
+   value can not be translated, it may still be useful.  In the case of
+   a client, the attribute string may be used for local display of
+   ownership.
+
+5.5 Permissions
+
+   The `permissions' field contains a bit mask of file permissions as
+   defined by POSIX [1].
+
+5.6 Times
+
+   The 'atime', 'createtime', and 'mtime' contain the access, creation,
+   and modification times of the files, respectively.   They are
+   represented as seconds from Jan 1, 1970 in UTC.
+
+   A negative value indicates number of seconds before Jan 1, 1970.  In
+   both cases, if the SSH_FILEXFER_ATTR_SUBSECOND_TIMES flag is set, the
+   nseconds field is to be added to the seconds field for the final time
+   representation.  For example, if the time to be represented is
+   one-half second before 0 hour January 1, 1970, the seconds field
+   would have a value of negative one (-1) and the nseconds fields would
+   have a value of one-half second (500000000).  Values greater than
+   999,999,999 for nseconds are considered invalid.
+
+5.7 ACL
+
+   The 'ACL' field contains an ACL similar to that defined in section
+   5.9 of NFS version 4 Protocol [3].
+
+   	uint32   ace-count
+
+   	repeated ace-count time:
+   	uint32   ace-type
+   	uint32   ace-flag
+   	uint32   ace-mask
+   	string   who [UTF-8]
+
+   ace-type is one of the following four values (taken from NFS Version
+   4 Protocol [3]:
+
+
+
+
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+Galbraith, et al.        Expires June 18, 2003                 [Page 12]
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+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+   	const ACE4_ACCESS_ALLOWED_ACE_TYPE      = 0x00000000;
+   	const ACE4_ACCESS_DENIED_ACE_TYPE       = 0x00000001;
+   	const ACE4_SYSTEM_AUDIT_ACE_TYPE        = 0x00000002;
+   	const ACE4_SYSTEM_ALARM_ACE_TYPE        = 0x00000003;
+
+   ace-flag is a combination of the following flag values.  See NFS
+   Version 4 Protocol [3] section 5.9.2:
+
+   	const ACE4_FILE_INHERIT_ACE             = 0x00000001;
+   	const ACE4_DIRECTORY_INHERIT_ACE        = 0x00000002;
+   	const ACE4_NO_PROPAGATE_INHERIT_ACE     = 0x00000004;
+   	const ACE4_INHERIT_ONLY_ACE             = 0x00000008;
+   	const ACE4_SUCCESSFUL_ACCESS_ACE_FLAG   = 0x00000010;
+   	const ACE4_FAILED_ACCESS_ACE_FLAG       = 0x00000020;
+   	const ACE4_IDENTIFIER_GROUP             = 0x00000040;
+
+   ace-mask is any combination of the following flags (taken from NFS
+   Version 4 Protocol [3] section 5.9.3:
+
+   	const ACE4_READ_DATA            = 0x00000001;
+   	const ACE4_LIST_DIRECTORY       = 0x00000001;
+   	const ACE4_WRITE_DATA           = 0x00000002;
+   	const ACE4_ADD_FILE             = 0x00000002;
+   	const ACE4_APPEND_DATA          = 0x00000004;
+   	const ACE4_ADD_SUBDIRECTORY     = 0x00000004;
+   	const ACE4_READ_NAMED_ATTRS     = 0x00000008;
+   	const ACE4_WRITE_NAMED_ATTRS    = 0x00000010;
+   	const ACE4_EXECUTE              = 0x00000020;
+   	const ACE4_DELETE_CHILD         = 0x00000040;
+   	const ACE4_READ_ATTRIBUTES      = 0x00000080;
+   	const ACE4_WRITE_ATTRIBUTES     = 0x00000100;
+   	const ACE4_DELETE               = 0x00010000;
+   	const ACE4_READ_ACL             = 0x00020000;
+   	const ACE4_WRITE_ACL            = 0x00040000;
+   	const ACE4_WRITE_OWNER          = 0x00080000;
+   	const ACE4_SYNCHRONIZE          = 0x00100000;
+
+   who is a UTF-8 string of the form described in 'Owner and Group'
+   (Section 5.4)
+
+   Also, as per '5.9.4 ACE who' [3] there are several identifiers that
+   need to be understood universally.  Some of these identifiers cannot
+   be understood when an client access the server, but have meaning when
+   a local process accesses the file.  The ability to display and modify
+   these permissions is permitted over SFTP.
+
+      OWNER         The owner of the file.
+
+
+
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+Internet-Draft         SSH File Transfer Protocol          December 2002
+
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+      GROUP         The group associated with the file.
+
+      EVERYONE      The world.
+
+      INTERACTIVE   Accessed from an interactive terminal.
+
+      NETWORK       Accessed via the network.
+
+      DIALUP        Accessed as a dialup user to the server.
+
+      BATCH         Accessed from a batch job.
+
+      ANONYMOUS     Accessed without any authentication.
+
+      AUTHENTICATED Any authenticated user (opposite of ANONYMOUS).
+
+      SERVICE       Access from a system service.
+
+   To avoid conflict, these special identifiers are distinguish by an
+   appended "@" and should appear in the form "xxxx@" (note: no domain
+   name after the "@").  For example: ANONYMOUS@.
+
+5.8 Extended attributes
+
+   The SSH_FILEXFER_ATTR_EXTENDED flag provides a general extension
+   mechanism for vendor-specific extensions.  If the flag is specified,
+   then the `extended_count' field is present.  It specifies the number
+   of extended_type-extended_data pairs that follow.  Each of these
+   pairs specifies an extended attribute.  For each of the attributes,
+   the extended_type field should be a string of the format
+   "name@domain", where "domain" is a valid, registered domain name and
+   "name" identifies the method.  The IETF may later standardize certain
+   names that deviate from this format (e.g., that do not contain the
+   "@" sign).  The interpretation of `extended_data' depends on the
+   type.  Implementations SHOULD ignore extended data fields that they
+   do not understand.
+
+   Additional fields can be added to the attributes by either defining
+   additional bits to the flags field to indicate their presence, or by
+   defining extended attributes for them.  The extended attributes
+   mechanism is recommended for most purposes; additional flags bits
+   should only be defined by an IETF standards action that also
+   increments the protocol version number.  The use of such new fields
+   MUST be negotiated by the version number in the protocol exchange.
+   It is a protocol error if a packet with unsupported protocol bits is
+   received.
+
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 14]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+6. Requests From the Client to the Server
+
+   Requests from the client to the server represent the various file
+   system operations.  Each request begins with an `id' field, which is
+   a 32-bit identifier identifying the request (selected by the client).
+   The same identifier will be returned in the response to the request.
+   One possible implementation is a monotonically increasing request
+   sequence number (modulo 2^32).
+
+   Many operations in the protocol operate on open files.  The
+   SSH_FXP_OPEN request can return a file handle (which is an opaque
+   variable-length string) which may be used to access the file later
+   (e.g.  in a read operation).  The client MUST NOT send requests the
+   server with bogus or closed handles.  However, the server MUST
+   perform adequate checks on the handle in order to avoid security
+   risks due to fabricated handles.
+
+   This design allows either stateful and stateless server
+   implementation, as well as an implementation which caches state
+   between requests but may also flush it.  The contents of the file
+   handle string are entirely up to the server and its design.  The
+   client should not modify or attempt to interpret the file handle
+   strings.
+
+   The file handle strings MUST NOT be longer than 256 bytes.
+
+6.1 Request Synchronization and Reordering
+
+   The protocol and implementations MUST process requests relating to
+   the same file in the order in which they are received.  In other
+   words, if an application submits multiple requests to the server, the
+   results in the responses will be the same as if it had sent the
+   requests one at a time and waited for the response in each case.  For
+   example, the server may process non-overlapping read/write requests
+   to the same file in parallel, but overlapping reads and writes cannot
+   be reordered or parallelized.  However, there are no ordering
+   restrictions on the server for processing requests from two different
+   file transfer connections.  The server may interleave and parallelize
+   them at will.
+
+   There are no restrictions on the order in which responses to
+   outstanding requests are delivered to the client, except that the
+   server must ensure fairness in the sense that processing of no
+   request will be indefinitely delayed even if the client is sending
+   other requests so that there are multiple outstanding requests all
+   the time.
+
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 15]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+6.2 File Names
+
+   This protocol represents file names as strings.  File names are
+   assumed to use the slash ('/') character as a directory separator.
+
+   File names starting with a slash are "absolute", and are relative to
+   the root of the file system.  Names starting with any other character
+   are relative to the user's default directory (home directory).  Note
+   that identifying the user is assumed to take place outside of this
+   protocol.
+
+   Servers SHOULD interpret a path name component ".." as referring to
+   the parent directory, and "." as referring to the current directory.
+   If the server implementation limits access to certain parts of the
+   file system, it must be extra careful in parsing file names when
+   enforcing such restrictions.  There have been numerous reported
+   security bugs where a ".." in a path name has allowed access outside
+   the intended area.
+
+   An empty path name is valid, and it refers to the user's default
+   directory (usually the user's home directory).
+
+   Otherwise, no syntax is defined for file names by this specification.
+   Clients should not make any other assumptions; however, they can
+   splice path name components returned by SSH_FXP_READDIR together
+   using a slash ('/') as the separator, and that will work as expected.
+
+   In order to comply with IETF Policy on Character Sets and Languages
+   [2], all filenames are to be encoded in UTF-8.  The shortest valid
+   UTF-8 encoding of the UNICODE data MUST be used.  The server is
+   responsible for converting the UNICODE data to whatever canonical
+   form it requires.
+
+   For example, if the server requires that precomposed characters
+   always be used, the server MUST NOT assume the filename as sent by
+   the client has this attribute, but must do this normalization itself.
+
+   It is understood that the lack of well-defined semantics for file
+   names may cause interoperability problems between clients and servers
+   using radically different operating systems.  However, this approach
+   is known to work acceptably with most systems, and alternative
+   approaches that e.g.  treat file names as sequences of structured
+   components are quite complicated.
+
+6.3 Opening, Creating, and Closing Files
+
+   Files are opened and created using the SSH_FXP_OPEN message, whose
+   data part is as follows:
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 16]
+
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+
+
+   	uint32        id
+   	string        filename [UTF-8]
+   	uint32        pflags
+   	ATTRS         attrs
+
+   The `id' field is the request identifier as for all requests.
+
+   The `filename' field specifies the file name.  See Section ``File
+   Names'' for more information.
+
+   The `pflags' field is a bitmask.  The following bits have been
+   defined.
+
+   	#define SSH_FXF_READ            0x00000001
+   	#define SSH_FXF_WRITE           0x00000002
+   	#define SSH_FXF_APPEND          0x00000004
+   	#define SSH_FXF_CREAT           0x00000008
+   	#define SSH_FXF_TRUNC           0x00000010
+   	#define SSH_FXF_EXCL            0x00000020
+   	#define SSH_FXF_TEXT            0x00000040
+
+   These have the following meanings:
+
+   SSH_FXF_READ
+      Open the file for reading.
+
+   SSH_FXF_WRITE
+      Open the file for writing.  If both this and SSH_FXF_READ are
+      specified, the file is opened for both reading and writing.
+
+   SSH_FXF_APPEND
+      Force all writes to append data at the end of the file.  The
+      offset parameter to write will be ignored.
+
+   SSH_FXF_CREAT
+      If this flag is specified, then a new file will be created if one
+      does not already exist (if O_TRUNC is specified, the new file will
+      be truncated to zero length if it previously exists).
+
+   SSH_FXF_TRUNC
+      Forces an existing file with the same name to be truncated to zero
+      length when creating a file by specifying SSH_FXF_CREAT.
+      SSH_FXF_CREAT MUST also be specified if this flag is used.
+
+   SSH_FXF_EXCL
+      Causes the request to fail if the named file already exists.
+      SSH_FXF_CREAT MUST also be specified if this flag is used.
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 17]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+   SSH_FXF_TEXT
+      Indicates that the server should treat the file as text and
+      convert it to the canonical newline convention in use.  (See
+      Determining Server Newline Convention. (Section 4.3)
+
+      When a file is opened with the FXF_TEXT flag, the offset field in
+      both the read and write function are ignored.
+
+      Servers MUST correctly process multiple parallel reads and writes
+      correctly in this mode.  Naturally, it is permissible for them to
+      do this by serializing the requests.  It would not be possible for
+      a client to reliably detect a server that does not implement
+      parallel writes in time to prevent damage.
+
+      Clients SHOULD use the SSH_FXF_APPEND flag to append data to a
+      text file rather then using write with a calculated offset.
+
+      To support seeks on text file the following SSH_FXP_EXTENDED
+      packet is defined.
+
+
+
+   	string "text-seek"
+   	string file-handle
+   	uint64 line-number
+
+      line-number is the index of the line number to seek to, where byte
+      0 in the file is line number 0, and the byte directly following
+      the first newline sequence in the file is line number 1 and so on.
+
+      The response to a "text-seek" request is an SSH_FXP_STATUS
+      message.
+
+      An attempt to seek past the end-of-file should result in a
+      SSH_FX_EOF status.
+
+      Servers SHOULD support at least one "text-seek" in order to
+      support resume.  However, a client MUST be prepared to receive
+      SSH_FX_OP_UNSUPPORTED when attempting a "text-seek" operation.
+      The client can then try a fall-back strategy, if it has one.
+
+      Clients MUST be prepared to handle SSH_FX_OP_UNSUPPORTED returned
+      for read or write operations that are not sequential.
+
+   The `attrs' field specifies the initial attributes for the file.
+   Default values will be used for those attributes that are not
+   specified.  See Section ``File Attributes'' for more information.
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 18]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+   The response to this message will be either SSH_FXP_HANDLE (if the
+   operation is successful) or SSH_FXP_STATUS (if the operation fails).
+
+   A file is closed by using the SSH_FXP_CLOSE request.  Its data field
+   has the following format:
+
+   	uint32     id
+   	string     handle
+
+   where `id' is the request identifier, and `handle' is a handle
+   previously returned in the response to SSH_FXP_OPEN or
+   SSH_FXP_OPENDIR.  The handle becomes invalid immediately after this
+   request has been sent.
+
+   The response to this request will be a SSH_FXP_STATUS message.  One
+   should note that on some server platforms even a close can fail.
+   This can happen e.g.  if the server operating system caches writes,
+   and an error occurs while flushing cached writes during the close.
+
+6.4 Reading and Writing
+
+   Once a file has been opened, it can be read using the following
+   message:
+
+   	byte       SSH_FXP_READ
+   	uint32     id
+   	string     handle
+   	uint64     offset
+   	uint32     len
+
+   where `id' is the request identifier, `handle' is an open file handle
+   returned by SSH_FXP_OPEN, `offset' is the offset (in bytes) relative
+   to the beginning of the file from where to start reading, and `len'
+   is the maximum number of bytes to read.
+
+   In response to this request, the server will read as many bytes as it
+   can from the file (up to `len'), and return them in a SSH_FXP_DATA
+   message.  If an error occurs or EOF is encountered before reading any
+   data, the server will respond with SSH_FXP_STATUS.
+
+   For normal disk files, it is normally guaranteed that this will read
+   the specified number of bytes, or up to end of file.  However, if the
+   read length is very long, the server may truncate it if it doesn't
+   support packets of that length.  See General Packet Format (Section
+   3).
+
+   For e.g.  device files this may return fewer bytes than requested.
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 19]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+   Writing to a file is achieved using the following message:
+
+   	byte       SSH_FXP_WRITE
+   	uint32     id
+   	string     handle
+   	uint64     offset
+   	string     data
+
+   where `id' is a request identifier, `handle' is a file handle
+   returned by SSH_FXP_OPEN, `offset' is the offset (in bytes) from the
+   beginning of the file where to start writing, and `data' is the data
+   to be written.
+
+   The write will extend the file if writing beyond the end of the file.
+   It is legal to write way beyond the end of the file; the semantics
+   are to write zeroes from the end of the file to the specified offset
+   and then the data.  On most operating systems, such writes do not
+   allocate disk space but instead leave "holes" in the file.
+
+   The server responds to a write request with a SSH_FXP_STATUS message.
+
+6.5 Removing and Renaming Files
+
+   Files can be removed using the SSH_FXP_REMOVE message.  It has the
+   following format:
+
+   	uint32     id
+   	string     filename [UTF-8]
+
+   where `id' is the request identifier and `filename' is the name of
+   the file to be removed.  See Section ``File Names'' for more
+   information.  This request cannot be used to remove directories.
+
+   The server will respond to this request with a SSH_FXP_STATUS
+   message.
+
+   Files (and directories) can be renamed using the SSH_FXP_RENAME
+   message.  Its data is as follows:
+
+   	uint32     id
+   	string     oldpath [UTF-8]
+   	string     newpath [UTF-8]
+
+   where `id' is the request identifier, `oldpath' is the name of an
+   existing file or directory, and `newpath' is the new name for the
+   file or directory.  It is an error if there already exists a file
+   with the name specified by newpath.  The server may also fail rename
+   requests in other situations, for example if `oldpath' and `newpath'
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 20]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+   point to different file systems on the server.
+
+   The server will respond to this request with a SSH_FXP_STATUS
+   message.
+
+6.6 Creating and Deleting Directories
+
+   New directories can be created using the SSH_FXP_MKDIR request.  It
+   has the following format:
+
+   	uint32     id
+   	string     path [UTF-8]
+   	ATTRS      attrs
+
+   where `id' is the request identifier.
+
+   `path' specifies the directory to be created.  See Section ``File
+   Names'' for more information on file names.
+
+   `attrs' specifies the attributes that should be applied to it upon
+   creation.  Attributes are discussed in more detail in Section ``File
+   Attributes''.
+
+   The server will respond to this request with a SSH_FXP_STATUS
+   message.  If a file or directory with the specified path already
+   exists, an error will be returned.
+
+   Directories can be removed using the SSH_FXP_RMDIR request, which has
+   the following format:
+
+   	uint32     id
+   	string     path [UTF-8]
+
+   where `id' is the request identifier, and `path' specifies the
+   directory to be removed.  See Section ``File Names'' for more
+   information on file names.
+
+   The server responds to this request with a SSH_FXP_STATUS message.
+   Errors may be returned from this operation for various reasons,
+   including, but not limited to, the path does not exist, the path does
+   not refer to a directory object, the directory is not empty, or the
+   user has insufficient access or permission to perform the requested
+   operation.
+
+6.7 Scanning Directories
+
+   The files in a directory can be listed using the SSH_FXP_OPENDIR and
+   SSH_FXP_READDIR requests.  Each SSH_FXP_READDIR request returns one
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 21]
+
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+
+
+   or more file names with full file attributes for each file.  The
+   client should call SSH_FXP_READDIR repeatedly until it has found the
+   file it is looking for or until the server responds with a
+   SSH_FXP_STATUS message indicating an error (normally SSH_FX_EOF if
+   there are no more files in the directory).  The client should then
+   close the handle using the SSH_FXP_CLOSE request.
+
+   The SSH_FXP_OPENDIR opens a directory for reading.  It has the
+   following format:
+
+   	uint32     id
+   	string     path [UTF-8]
+
+   where `id' is the request identifier and `path' is the path name of
+   the directory to be listed (without any trailing slash).  See Section
+   ``File Names'' for more information on file names.  This will return
+   an error if the path does not specify a directory or if the directory
+   is not readable.  The server will respond to this request with either
+   a SSH_FXP_HANDLE or a SSH_FXP_STATUS message.
+
+   Once the directory has been successfully opened, files (and
+   directories) contained in it can be listed using SSH_FXP_READDIR
+   requests.  These are of the format
+
+   	uint32     id
+   	string     handle
+
+   where `id' is the request identifier, and `handle' is a handle
+   returned by SSH_FXP_OPENDIR.  (It is a protocol error to attempt to
+   use an ordinary file handle returned by SSH_FXP_OPEN.)
+
+   The server responds to this request with either a SSH_FXP_NAME or a
+   SSH_FXP_STATUS message.  One or more names may be returned at a time.
+   Full status information is returned for each name in order to speed
+   up typical directory listings.
+
+   If there are no more names available to be read, the server MUST
+   respond with a SSH_FXP_STATUS message with error code of SSH_FX_EOF.
+
+   When the client no longer wishes to read more names from the
+   directory, it SHOULD call SSH_FXP_CLOSE for the handle.  The handle
+   should be closed regardless of whether an error has occurred or not.
+
+6.8 Retrieving File Attributes
+
+   Very often, file attributes are automatically returned by
+   SSH_FXP_READDIR.  However, sometimes there is need to specifically
+   retrieve the attributes for a named file.  This can be done using the
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 22]
+
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+
+
+   SSH_FXP_STAT, SSH_FXP_LSTAT and SSH_FXP_FSTAT requests.
+
+   SSH_FXP_STAT and SSH_FXP_LSTAT only differ in that SSH_FXP_STAT
+   follows symbolic links on the server, whereas SSH_FXP_LSTAT does not
+   follow symbolic links.  Both have the same format:
+
+   	uint32     id
+   	string     path [UTF-8]
+   	uint32     flags
+
+   where `id' is the request identifier, and `path' specifies the file
+   system object for which status is to be returned.  The server
+   responds to this request with either SSH_FXP_ATTRS or SSH_FXP_STATUS.
+
+   The flags field specify the attribute flags in which the client has
+   particular interest.  This is a hint to the server.  For example,
+   because retrieving owner / group and acl information can be an
+   expensive operation under some operating systems, the server may
+   choose not to retrieve this information unless the client expresses a
+   specific interest in it.
+
+   The client has no guarantee the server will provide all the fields
+   that it has expressed an interest in.
+
+   SSH_FXP_FSTAT differs from the others in that it returns status
+   information for an open file (identified by the file handle).  Its
+   format is as follows:
+
+   	uint32     id
+   	string     handle
+   	uint32     flags
+
+   where `id' is the request identifier and `handle' is a file handle
+   returned by SSH_FXP_OPEN.  The server responds to this request with
+   SSH_FXP_ATTRS or SSH_FXP_STATUS.
+
+6.9 Setting File Attributes
+
+   File attributes may be modified using the SSH_FXP_SETSTAT and
+   SSH_FXP_FSETSTAT requests.  These requests are used for operations
+   such as changing the ownership, permissions or access times, as well
+   as for truncating a file.
+
+   The SSH_FXP_SETSTAT request is of the following format:
+
+
+
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 23]
+
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+
+
+   	uint32     id
+   	string     path [UTF-8]
+   	ATTRS      attrs
+
+   where `id' is the request identifier, `path' specifies the file
+   system object (e.g.  file or directory) whose attributes are to be
+   modified, and `attrs' specifies the modifications to be made to its
+   attributes.  Attributes are discussed in more detail in Section
+   ``File Attributes''.
+
+   An error will be returned if the specified file system object does
+   not exist or the user does not have sufficient rights to modify the
+   specified attributes.  The server responds to this request with a
+   SSH_FXP_STATUS message.
+
+   The SSH_FXP_FSETSTAT request modifies the attributes of a file which
+   is already open.  It has the following format:
+
+   	uint32     id
+   	string     handle
+   	ATTRS      attrs
+
+   where `id' is the request identifier, `handle' (MUST be returned by
+   SSH_FXP_OPEN) identifies the file whose attributes are to be
+   modified, and `attrs' specifies the modifications to be made to its
+   attributes.  Attributes are discussed in more detail in Section
+   ``File Attributes''.  The server will respond to this request with
+   SSH_FXP_STATUS.
+
+6.10 Dealing with Symbolic links
+
+   The SSH_FXP_READLINK request may be used to read the target of a
+   symbolic link.  It would have a data part as follows:
+
+   	uint32     id
+   	string     path [UTF-8]
+
+   where `id' is the request identifier and `path' specifies the path
+   name of the symlink to be read.
+
+   The server will respond with a SSH_FXP_NAME packet containing only
+   one name and a dummy attributes value.  The name in the returned
+   packet contains the target of the link.  If an error occurs, the
+   server may respond with SSH_FXP_STATUS.
+
+   The SSH_FXP_SYMLINK request will create a symbolic link on the
+   server.  It is of the following format
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 24]
+
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+
+
+   	uint32     id
+   	string     linkpath   [UTF-8]
+   	string     targetpath [UTF-8]
+
+   where `id' is the request identifier, `linkpath' specifies the path
+   name of the symlink to be created and `targetpath' specifies the
+   target of the symlink.  The server shall respond with a
+   SSH_FXP_STATUS indicating either success (SSH_FX_OK) or an error
+   condition.
+
+6.11 Canonicalizing the Server-Side Path Name
+
+   The SSH_FXP_REALPATH request can be used to have the server
+   canonicalize any given path name to an absolute path.  This is useful
+   for converting path names containing ".." components or relative
+   pathnames without a leading slash into absolute paths.  The format of
+   the request is as follows:
+
+   	uint32     id
+   	string     path [UTF-8]
+
+   where `id' is the request identifier and `path' specifies the path
+   name to be canonicalized.  The server will respond with a
+   SSH_FXP_NAME packet containing the name in canonical form and a dummy
+   attributes value.  If an error occurs, the server may also respond
+   with SSH_FXP_STATUS.
+
+6.11.1 Best practice for dealing with paths
+
+   The client SHOULD treat the results of SSH_FXP_REALPATH as a
+   canonical absolute path, even if the path does not appear to be
+   absolute.  A client that use REALPATH(".") and treats the result as
+   absolute, even if there is no leading slash, will continue to
+   function correctly, even when talking to a Windows NT or VMS style
+   system, where absolute paths may not begin with a slash.
+
+   For example, if the client wishes to change directory up, and the
+   server has returned "c:/x/y/z" from REALPATH, the client SHOULD use
+   "c:/x/y/z/..".
+
+   As a second example, if the client wishes to open the file "x.txt" in
+   the current directory, and server has returned "dka100:/x/y/z" as the
+   canonical path of the directory, the client SHOULD open "dka100:/x/y/
+   z/x.txt"
+
+
+
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 25]
+
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+
+
+7. Responses from the Server to the Client
+
+   The server responds to the client using one of a few response
+   packets.  All requests can return a SSH_FXP_STATUS response upon
+   failure.  When the operation is successful, any of the responses may
+   be returned (depending on the operation).  If no data needs to be
+   returned to the client, the SSH_FXP_STATUS response with SSH_FX_OK
+   status is appropriate.  Otherwise, the SSH_FXP_HANDLE message is used
+   to return a file handle (for SSH_FXP_OPEN and SSH_FXP_OPENDIR
+   requests), SSH_FXP_DATA is used to return data from SSH_FXP_READ,
+   SSH_FXP_NAME is used to return one or more file names from a
+   SSH_FXP_READDIR or SSH_FXP_REALPATH request, and SSH_FXP_ATTRS is
+   used to return file attributes from SSH_FXP_STAT, SSH_FXP_LSTAT, and
+   SSH_FXP_FSTAT requests.
+
+   Exactly one response will be returned for each request.  Each
+   response packet contains a request identifier which can be used to
+   match each response with the corresponding request.  Note that it is
+   legal to have several requests outstanding simultaneously, and the
+   server is allowed to send responses to them in a different order from
+   the order in which the requests were sent (the result of their
+   execution, however, is guaranteed to be as if they had been processed
+   one at a time in the order in which the requests were sent).
+
+   Response packets are of the same general format as request packets.
+   Each response packet begins with the request identifier.
+
+   The format of the data portion of the SSH_FXP_STATUS response is as
+   follows:
+
+   	uint32     id
+   	uint32     error/status code
+   	string     error message (ISO-10646 UTF-8 [RFC-2279])
+   	string     language tag (as defined in [RFC-1766])
+
+   where `id' is the request identifier, and `error/status code'
+   indicates the result of the requested operation.  The value SSH_FX_OK
+   indicates success, and all other values indicate failure.
+
+   Currently, the following values are defined (other values may be
+   defined by future versions of this protocol):
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 26]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+   	#define SSH_FX_OK                            0
+   	#define SSH_FX_EOF                           1
+   	#define SSH_FX_NO_SUCH_FILE                  2
+   	#define SSH_FX_PERMISSION_DENIED             3
+   	#define SSH_FX_FAILURE                       4
+   	#define SSH_FX_BAD_MESSAGE                   5
+   	#define SSH_FX_NO_CONNECTION                 6
+   	#define SSH_FX_CONNECTION_LOST               7
+   	#define SSH_FX_OP_UNSUPPORTED                8
+   	#define SSH_FX_INVALID_HANDLE                9
+   	#define SSH_FX_NO_SUCH_PATH                  10
+   	#define SSH_FX_FILE_ALREADY_EXISTS           11
+   	#define SSH_FX_WRITE_PROTECT                 12
+   	#define SSH_FX_NO_MEDIA                      13
+
+   SSH_FX_OK
+      Indicates successful completion of the operation.
+
+   SSH_FX_EOF
+      indicates end-of-file condition; for SSH_FX_READ it means that no
+      more data is available in the file, and for SSH_FX_READDIR it
+      indicates that no more files are contained in the directory.
+
+   SSH_FX_NO_SUCH_FILE
+      is returned when a reference is made to a file which does not
+      exist.
+
+   SSH_FX_PERMISSION_DENIED
+      is returned when the authenticated user does not have sufficient
+      permissions to perform the operation.
+
+   SSH_FX_FAILURE
+      is a generic catch-all error message; it should be returned if an
+      error occurs for which there is no more specific error code
+      defined.
+
+   SSH_FX_BAD_MESSAGE
+      may be returned if a badly formatted packet or protocol
+      incompatibility is detected.
+
+   SSH_FX_NO_CONNECTION
+      is a pseudo-error which indicates that the client has no
+      connection to the server (it can only be generated locally by the
+      client, and MUST NOT be returned by servers).
+
+   SSH_FX_CONNECTION_LOST
+      is a pseudo-error which indicates that the connection to the
+      server has been lost (it can only be generated locally by the
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 27]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+      client, and MUST NOT be returned by servers).
+
+   SSH_FX_OP_UNSUPPORTED
+      indicates that an attempt was made to perform an operation which
+      is not supported for the server (it may be generated locally by
+      the client if e.g.  the version number exchange indicates that a
+      required feature is not supported by the server, or it may be
+      returned by the server if the server does not implement an
+      operation).
+
+   SSH_FX_INVALID_HANDLE
+      The handle value was invalid.
+
+   SSH_FX_NO_SUCH_PATH
+      The file path does not exist or is invalid.
+
+   SSH_FX_FILE_ALREADY_EXISTS
+      The file already exists.
+
+   SSH_FX_WRITE_PROTECT
+      The file is on read only media, or the media is write protected.
+
+   SSH_FX_NO_MEDIA
+      The requested operation can not be completed because there is no
+      media available in the drive.
+
+   The SSH_FXP_HANDLE response has the following format:
+
+   	uint32     id
+   	string     handle
+
+   where `id' is the request identifier, and `handle' is an arbitrary
+   string that identifies an open file or directory on the server.  The
+   handle is opaque to the client; the client MUST NOT attempt to
+   interpret or modify it in any way.  The length of the handle string
+   MUST NOT exceed 256 data bytes.
+
+   The SSH_FXP_DATA response has the following format:
+
+   	uint32     id
+   	string     data
+
+   where `id' is the request identifier, and `data' is an arbitrary byte
+   string containing the requested data.  The data string may be at most
+   the number of bytes requested in a SSH_FXP_READ request, but may also
+   be shorter if end of file is reached or if the read is from something
+   other than a regular file.
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 28]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+   The SSH_FXP_NAME response has the following format:
+
+   	uint32     id
+   	uint32     count
+   	repeats count times:
+   		string     filename [UTF-8]
+   		ATTRS      attrs
+
+   where `id' is the request identifier, `count' is the number of names
+   returned in this response, and the remaining fields repeat `count'
+   times (so that all three fields are first included for the first
+   file, then for the second file, etc).  In the repeated part,
+   `filename' is a file name being returned (for SSH_FXP_READDIR, it
+   will be a relative name within the directory, without any path
+   components; for SSH_FXP_REALPATH it will be an absolute path name),
+   and `attrs' is the attributes of the file as described in Section
+   ``File Attributes''.
+
+   The SSH_FXP_ATTRS response has the following format:
+
+   	uint32     id
+   	ATTRS      attrs
+
+   where `id' is the request identifier, and `attrs' is the returned
+   file attributes as described in Section ``File Attributes''.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 29]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+8. Vendor-Specific Extensions
+
+   The SSH_FXP_EXTENDED request provides a generic extension mechanism
+   for adding vendor-specific commands.  The request has the following
+   format:
+
+   	uint32     id
+   	string     extended-request
+   	... any request-specific data ...
+
+   where `id' is the request identifier, and `extended-request' is a
+   string of the format "name@domain", where domain is an internet
+   domain name of the vendor defining the request.  The rest of the
+   request is completely vendor-specific, and servers should only
+   attempt to interpret it if they recognize the `extended-request'
+   name.
+
+   The server may respond to such requests using any of the response
+   packets defined in Section ``Responses from the Server to the
+   Client''.  Additionally, the server may also respond with a
+   SSH_FXP_EXTENDED_REPLY packet, as defined below.  If the server does
+   not recognize the `extended-request' name, then the server MUST
+   respond with SSH_FXP_STATUS with error/status set to
+   SSH_FX_OP_UNSUPPORTED.
+
+   The SSH_FXP_EXTENDED_REPLY packet can be used to carry arbitrary
+   extension-specific data from the server to the client.  It is of the
+   following format:
+
+   	uint32     id
+   	... any request-specific data ...
+
+   There is a range of packet types reserved for use by extensions.  In
+   order to avoid collision, extensions that turn on the use of
+   additional packet types should determine those numbers dynamically.
+
+   The suggested way of doing this is have an extension request from the
+   client to the server that enables the extension; the extension
+   response from the server to the client would specify the actual type
+   values to use, in additional to any other data.
+
+   Extension authors should be mindful of the limited range of packet
+   types available (there are only 45 values available) and avoid
+   requiring a new packet type where possible.
+
+
+
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 30]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+9. Security Considerations
+
+   This protocol assumes that it is run over a secure channel and that
+   the endpoints of the channel have been authenticated.  Thus, this
+   protocol assumes that it is externally protected from network-level
+   attacks.
+
+   This protocol provides file system access to arbitrary files on the
+   server (only constrained by the server implementation).  It is the
+   responsibility of the server implementation to enforce any access
+   controls that may be required to limit the access allowed for any
+   particular user (the user being authenticated externally to this
+   protocol, typically using the SSH User Authentication Protocol [8].
+
+   Care must be taken in the server implementation to check the validity
+   of received file handle strings.  The server should not rely on them
+   directly; it MUST check the validity of each handle before relying on
+   it.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 31]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+10. Changes from previous protocol versions
+
+   The SSH File Transfer Protocol has changed over time, before it's
+   standardization.  The following is a description of the incompatible
+   changes between different versions.
+
+10.1 Changes between versions 4 and 3
+
+   Many of the changes between version 4 and version 3 are to the
+   attribute structure to make it more flexible for non-unix platforms.
+
+   o  Clarify the use of stderr by the server.
+
+   o  Clarify handling of very large read requests by the server.
+
+   o  Make all filenames UTF-8.
+
+   o  Added 'newline' extension.
+
+   o  Made time fields 64 bit, and optionally have nanosecond resultion.
+
+   o  Made file attribute owner and group strings so they can actually
+      be used on disparate systems.
+
+   o  Added createtime field, and added separate flags for atime,
+      createtime, and mtime so they can be set separately.
+
+   o  Split the file type out of the permissions field and into it's own
+      field (which is always present.)
+
+   o  Added acl attribute.
+
+   o  Added SSH_FXF_TEXT file open flag.
+
+   o  Added flags field to the get stat commands so that the client can
+      specifically request information the server might not normally
+      included for performance reasons.
+
+   o  Removed the long filename from the names structure-- it can now be
+      built from information available in the attrs structure.
+
+   o  Added reserved range of packet numbers for extensions.
+
+   o  Added several additional error codes.
+
+
+
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 32]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+10.2 Changes between versions 3 and 2
+
+   o  The SSH_FXP_READLINK and SSH_FXP_SYMLINK messages were added.
+
+   o  The SSH_FXP_EXTENDED and SSH_FXP_EXTENDED_REPLY messages were
+      added.
+
+   o  The SSH_FXP_STATUS message was changed to include fields `error
+      message' and `language tag'.
+
+
+10.3 Changes between versions 2 and 1
+
+   o  The SSH_FXP_RENAME message was added.
+
+
+10.4 Changes between versions 1 and 0
+
+   o  Implementation changes, no actual protocol changes.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 33]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+11. Trademark Issues
+
+   "ssh" is a registered trademark of SSH Communications Security Corp
+   in the United States and/or other countries.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 34]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+References
+
+   [1]  Dierks, T., Allen, C., Treese, W., Karlton, P., Freier, A. and
+        P. Kocher, "The TLS Protocol Version 1.0", RFC 2246, January
+        1999.
+
+   [2]  Alvestrand, H., "IETF Policy on Character Sets and Languages",
+        BCP 18, RFC 2277, January 1998.
+
+   [3]  Shepler, S., Callaghan, B., Robinson, D., Thurlow, R., Beame,
+        C., Eisler, M. and D. Noveck, "NFS version 4 Protocol", RFC
+        3010, December 2000.
+
+   [4]  Institute of Electrical and Electronics Engineers, "Information
+        Technology - Portable Operating System Interface (POSIX) - Part
+        1: System Application Program Interface (API) [C Language]",
+        IEEE Standard 1003.2, 1996.
+
+   [5]  Rinne, T., Ylonen, T., Kivinen, T., Saarinen, M. and S.
+        Lehtinen, "SSH Protocol Architecture",
+        draft-ietf-secsh-architecture-13 (work in progress), September
+        2002.
+
+   [6]  Rinne, T., Ylonen, T., Kivinen, T., Saarinen, M. and S.
+        Lehtinen, "SSH Protocol Transport Protocol",
+        draft-ietf-secsh-transport-15 (work in progress), September
+        2002.
+
+   [7]  Rinne, T., Ylonen, T., Kivinen, T., Saarinen, M. and S.
+        Lehtinen, "SSH Connection Protocol", draft-ietf-secsh-connect-16
+        (work in progress), September 2002.
+
+   [8]  Rinne, T., Ylonen, T., Kivinen, T., Saarinen, M. and S.
+        Lehtinen, "SSH Authentication Protocol",
+        draft-ietf-secsh-userauth-16 (work in progress), September 2002.
+
+
+Authors' Addresses
+
+   Joseph Galbraith
+   VanDyke Software
+   4848 Tramway Ridge Blvd
+   Suite 101
+   Albuquerque, NM  87111
+   US
+
+   Phone: +1 505 332 5700
+   EMail: [email protected]
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 35]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+   Tatu Ylonen
+   SSH Communications Security Corp
+   Fredrikinkatu 42
+   HELSINKI  FIN-00100
+   Finland
+
+   EMail: [email protected]
+
+
+   Sami Lehtinen
+   SSH Communications Security Corp
+   Fredrikinkatu 42
+   HELSINKI  FIN-00100
+   Finland
+
+   EMail: [email protected]
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 36]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+Intellectual Property Statement
+
+   The IETF takes no position regarding the validity or scope of any
+   intellectual property or other rights that might be claimed to
+   pertain to the implementation or use of the technology described in
+   this document or the extent to which any license under such rights
+   might or might not be available; neither does it represent that it
+   has made any effort to identify any such rights.  Information on the
+   IETF's procedures with respect to rights in standards-track and
+   standards-related documentation can be found in BCP-11.  Copies of
+   claims of rights made available for publication and any assurances of
+   licenses to be made available, or the result of an attempt made to
+   obtain a general license or permission for the use of such
+   proprietary rights by implementors or users of this specification can
+   be obtained from the IETF Secretariat.
+
+   The IETF invites any interested party to bring to its attention any
+   copyrights, patents or patent applications, or other proprietary
+   rights which may cover technology that may be required to practice
+   this standard.  Please address the information to the IETF Executive
+   Director.
+
+
+Full Copyright Statement
+
+   Copyright (C) The Internet Society (2002).  All Rights Reserved.
+
+   This document and translations of it may be copied and furnished to
+   others, and derivative works that comment on or otherwise explain it
+   or assist in its implementation may be prepared, copied, published
+   and distributed, in whole or in part, without restriction of any
+   kind, provided that the above copyright notice and this paragraph are
+   included on all such copies and derivative works.  However, this
+   document itself may not be modified in any way, such as by removing
+   the copyright notice or references to the Internet Society or other
+   Internet organizations, except as needed for the purpose of
+   developing Internet standards in which case the procedures for
+   copyrights defined in the Internet Standards process must be
+   followed, or as required to translate it into languages other than
+   English.
+
+   The limited permissions granted above are perpetual and will not be
+   revoked by the Internet Society or its successors or assignees.
+
+   This document and the information contained herein is provided on an
+   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
+   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
+   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 37]
+
+Internet-Draft         SSH File Transfer Protocol          December 2002
+
+
+   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
+   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+
+
+Acknowledgement
+
+   Funding for the RFC Editor function is currently provided by the
+   Internet Society.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Galbraith, et al.        Expires June 18, 2003                 [Page 38]
+
+
diff --git a/lib/ssh/doc/standard/draft-ietf-secsh-transport-17.2.ps b/lib/ssh/doc/standard/draft-ietf-secsh-transport-17.2.ps
new file mode 100644
index 0000000000..d692285b4e
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+(Network Working Group                                          T. Ylonen) s
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+(Internet-Draft                          SSH Communications Security Corp) s
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+(Expires: March 31, 2004                           D. Moffat, Editor, Ed.) s
+5 668 M
+(                                                   Sun Microsystems, Inc) s
+5 657 M
+(                                                                Oct 2003) s
+5 624 M
+(                      SSH Transport Layer Protocol) s
+5 613 M
+(                   draft-ietf-secsh-transport-17.txt) s
+5 591 M
+(Status of this Memo) s
+5 569 M
+(   This document is an Internet-Draft and is in full conformance with) s
+5 558 M
+(   all provisions of Section 10 of RFC2026.) s
+5 536 M
+(   Internet-Drafts are working documents of the Internet Engineering) s
+5 525 M
+(   Task Force \(IETF\), its areas, and its working groups. Note that other) s
+5 514 M
+(   groups may also distribute working documents as Internet-Drafts.) s
+5 492 M
+(   Internet-Drafts are draft documents valid for a maximum of six months) s
+5 481 M
+(   and may be updated, replaced, or obsoleted by other documents at any) s
+5 470 M
+(   time. It is inappropriate to use Internet-Drafts as reference) s
+5 459 M
+(   material or to cite them other than as "work in progress.") s
+5 437 M
+(   The list of current Internet-Drafts can be accessed at http://) s
+5 426 M
+(   www.ietf.org/ietf/1id-abstracts.txt.) s
+5 404 M
+(   The list of Internet-Draft Shadow Directories can be accessed at) s
+5 393 M
+(   http://www.ietf.org/shadow.html.) s
+5 371 M
+(   This Internet-Draft will expire on March 31, 2004.) s
+5 349 M
+(Copyright Notice) s
+5 327 M
+(   Copyright \(C\) The Internet Society \(2003\). All Rights Reserved.) s
+5 305 M
+(Abstract) s
+5 283 M
+(   SSH is a protocol for secure remote login and other secure network) s
+5 272 M
+(   services over an insecure network.) s
+5 250 M
+(   This document describes the SSH transport layer protocol which) s
+5 239 M
+(   typically runs on top of TCP/IP. The protocol can be used as a basis) s
+5 228 M
+(   for a number of secure network services. It provides strong) s
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+(   encryption, server authentication, and integrity protection. It may) s
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+(   also provide compression.) s
+5 184 M
+(   Key exchange method, public key algorithm, symmetric encryption) s
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+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(   all negotiated.) s
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+(   This document also describes the Diffie-Hellman key exchange method) s
+5 657 M
+(   and the minimal set of algorithms that are needed to implement the) s
+5 646 M
+(   SSH transport layer protocol.) s
+5 624 M
+(Table of Contents) s
+5 602 M
+(   1.    Contributors . . . . . . . . . . . . . . . . . . . . . . . .  3) s
+5 591 M
+(   2.    Introduction . . . . . . . . . . . . . . . . . . . . . . . .  3) s
+5 580 M
+(   3.    Conventions Used in This Document  . . . . . . . . . . . . .  3) s
+5 569 M
+(   4.    Connection Setup . . . . . . . . . . . . . . . . . . . . . .  3) s
+5 558 M
+(   4.1   Use over TCP/IP  . . . . . . . . . . . . . . . . . . . . . .  4) s
+5 547 M
+(   4.2   Protocol Version Exchange  . . . . . . . . . . . . . . . . .  4) s
+5 536 M
+(   4.3   Compatibility With Old SSH Versions  . . . . . . . . . . . .  4) s
+5 525 M
+(   4.3.1 Old Client, New Server . . . . . . . . . . . . . . . . . . .  5) s
+5 514 M
+(   4.3.2 New Client, Old Server . . . . . . . . . . . . . . . . . . .  5) s
+5 503 M
+(   5.    Binary Packet Protocol . . . . . . . . . . . . . . . . . . .  5) s
+5 492 M
+(   5.1   Maximum Packet Length  . . . . . . . . . . . . . . . . . . .  6) s
+5 481 M
+(   5.2   Compression  . . . . . . . . . . . . . . . . . . . . . . . .  7) s
+5 470 M
+(   5.3   Encryption . . . . . . . . . . . . . . . . . . . . . . . . .  7) s
+5 459 M
+(   5.4   Data Integrity . . . . . . . . . . . . . . . . . . . . . . .  9) s
+5 448 M
+(   5.5   Key Exchange Methods . . . . . . . . . . . . . . . . . . . . 10) s
+5 437 M
+(   5.6   Public Key Algorithms  . . . . . . . . . . . . . . . . . . . 11) s
+5 426 M
+(   6.    Key Exchange . . . . . . . . . . . . . . . . . . . . . . . . 13) s
+5 415 M
+(   6.1   Algorithm Negotiation  . . . . . . . . . . . . . . . . . . . 13) s
+5 404 M
+(   6.2   Output from Key Exchange . . . . . . . . . . . . . . . . . . 16) s
+5 393 M
+(   6.3   Taking Keys Into Use . . . . . . . . . . . . . . . . . . . . 17) s
+5 382 M
+(   7.    Diffie-Hellman Key Exchange  . . . . . . . . . . . . . . . . 18) s
+5 371 M
+(   7.1   diffie-hellman-group1-sha1 . . . . . . . . . . . . . . . . . 19) s
+5 360 M
+(   8.    Key Re-Exchange  . . . . . . . . . . . . . . . . . . . . . . 20) s
+5 349 M
+(   9.    Service Request  . . . . . . . . . . . . . . . . . . . . . . 21) s
+5 338 M
+(   10.   Additional Messages  . . . . . . . . . . . . . . . . . . . . 21) s
+5 327 M
+(   10.1  Disconnection Message  . . . . . . . . . . . . . . . . . . . 22) s
+5 316 M
+(   10.2  Ignored Data Message . . . . . . . . . . . . . . . . . . . . 22) s
+5 305 M
+(   10.3  Debug Message  . . . . . . . . . . . . . . . . . . . . . . . 23) s
+5 294 M
+(   10.4  Reserved Messages  . . . . . . . . . . . . . . . . . . . . . 23) s
+5 283 M
+(   11.   Summary of Message Numbers . . . . . . . . . . . . . . . . . 23) s
+5 272 M
+(   12.   IANA Considerations  . . . . . . . . . . . . . . . . . . . . 24) s
+5 261 M
+(   13.   Security Considerations  . . . . . . . . . . . . . . . . . . 24) s
+5 250 M
+(   14.   Intellectual Property  . . . . . . . . . . . . . . . . . . . 24) s
+5 239 M
+(   15.   Additional Information . . . . . . . . . . . . . . . . . . . 24) s
+5 228 M
+(         Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 26) s
+5 217 M
+(         Normative  . . . . . . . . . . . . . . . . . . . . . . . . . 25) s
+5 206 M
+(         Informative  . . . . . . . . . . . . . . . . . . . . . . . . 25) s
+5 195 M
+(   A.    Contibutors  . . . . . . . . . . . . . . . . . . . . . . . . 27) s
+5 184 M
+(         Intellectual Property and Copyright Statements . . . . . . . 28) s
+5 129 M
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+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(1. Contributors) s
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+(   The major original contributors of this document were: Tatu Ylonen,) s
+5 657 M
+(   Tero Kivinen, Timo J. Rinne, Sami Lehtinen \(all of SSH Communications) s
+5 646 M
+(   Security Corp\), and Markku-Juhani O. Saarinen \(University of) s
+5 635 M
+(   Jyvaskyla\)) s
+5 613 M
+(   The document editor is: [email protected].  Comments on this) s
+5 602 M
+(   internet draft should be sent to the IETF SECSH working group,) s
+5 591 M
+(   details at: http://ietf.org/html.charters/secsh-charter.html) s
+5 569 M
+(2. Introduction) s
+5 547 M
+(   The SSH transport layer is a secure low level transport protocol. It) s
+5 536 M
+(   provides strong encryption, cryptographic host authentication, and) s
+5 525 M
+(   integrity protection.) s
+5 503 M
+(   Authentication in this protocol level is host-based; this protocol) s
+5 492 M
+(   does not perform user authentication. A higher level protocol for) s
+5 481 M
+(   user authentication can be designed on top of this protocol.) s
+5 459 M
+(   The protocol has been designed to be simple, flexible, to allow) s
+5 448 M
+(   parameter negotiation, and to minimize the number of round-trips.) s
+5 437 M
+(   Key exchange method, public key algorithm, symmetric encryption) s
+5 426 M
+(   algorithm, message authentication algorithm, and hash algorithm are) s
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+(   all negotiated.  It is expected that in most environments, only 2) s
+5 404 M
+(   round-trips will be needed for full key exchange, server) s
+5 393 M
+(   authentication, service request, and acceptance notification of) s
+5 382 M
+(   service request.  The worst case is 3 round-trips.) s
+5 360 M
+(3. Conventions Used in This Document) s
+5 338 M
+(   The keywords "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT",) s
+5 327 M
+(   and "MAY" that appear in this document are to be interpreted as) s
+5 316 M
+(   described in [RFC2119].) s
+5 294 M
+(   The used data types and terminology are specified in the architecture) s
+5 283 M
+(   document [SSH-ARCH].) s
+5 261 M
+(   The architecture document also discusses the algorithm naming) s
+5 250 M
+(   conventions that MUST be used with the SSH protocols.) s
+5 228 M
+(4. Connection Setup) s
+5 206 M
+(   SSH works over any 8-bit clean, binary-transparent transport.  The) s
+5 195 M
+(   underlying transport SHOULD protect against transmission errors as) s
+5 184 M
+(   such errors cause the SSH connection to terminate.) s
+5 129 M
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+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(   The client initiates the connection.) s
+5 668 M
+(4.1 Use over TCP/IP) s
+5 646 M
+(   When used over TCP/IP, the server normally listens for connections on) s
+5 635 M
+(   port 22.  This port number has been registered with the IANA, and has) s
+5 624 M
+(   been officially assigned for SSH.) s
+5 602 M
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+5 580 M
+(   When the connection has been established, both sides MUST send an) s
+5 569 M
+(   identification string of the form "SSH-protoversion-softwareversion) s
+5 558 M
+(   comments", followed by carriage return and newline characters \(ASCII) s
+5 547 M
+(   13 and 10, respectively\).  Both sides MUST be able to process) s
+5 536 M
+(   identification strings without carriage return character.  No null) s
+5 525 M
+(   character is sent.  The maximum length of the string is 255) s
+5 514 M
+(   characters, including the carriage return and newline.) s
+5 492 M
+(   The part of the identification string preceding carriage return and) s
+5 481 M
+(   newline is used in the Diffie-Hellman key exchange \(see Section) s
+5 470 M
+(   Section 7\).) s
+5 448 M
+(   The server MAY send other lines of data before sending the version) s
+5 437 M
+(   string.  Each line SHOULD be terminated by a carriage return and) s
+5 426 M
+(   newline.  Such lines MUST NOT begin with "SSH-", and SHOULD be) s
+5 415 M
+(   encoded in ISO-10646 UTF-8 [RFC2279] \(language is not specified\).) s
+5 404 M
+(   Clients MUST be able to process such lines; they MAY be silently) s
+5 393 M
+(   ignored, or MAY be displayed to the client user; if they are) s
+5 382 M
+(   displayed, control character filtering discussed in [SSH-ARCH] SHOULD) s
+5 371 M
+(   be used.  The primary use of this feature is to allow TCP-wrappers to) s
+5 360 M
+(   display an error message before disconnecting.) s
+5 338 M
+(   Version strings MUST consist of printable US-ASCII characters, not) s
+5 327 M
+(   including whitespaces or a minus sign \(-\).  The version string is) s
+5 316 M
+(   primarily used to trigger compatibility extensions and to indicate) s
+5 305 M
+(   the capabilities of an implementation. The comment string should) s
+5 294 M
+(   contain additional information that might be useful in solving user) s
+5 283 M
+(   problems.) s
+5 261 M
+(   The protocol version described in this document is 2.0.) s
+5 239 M
+(   Key exchange will begin immediately after sending this identifier.) s
+5 228 M
+(   All packets following the identification string SHALL use the binary) s
+5 217 M
+(   packet protocol, to be described below.) s
+5 195 M
+(4.3 Compatibility With Old SSH Versions) s
+5 173 M
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+5 129 M
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+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 5 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(   way that is compatible with the installed SSH clients and servers) s
+5 679 M
+(   that use an older version of the protocol.  Information in this) s
+5 668 M
+(   section is only relevant for implementations supporting compatibility) s
+5 657 M
+(   with SSH versions 1.x.  There is no standards track or informational) s
+5 646 M
+(   draft available that defines the SSH 1.x protocol.  The only known) s
+5 635 M
+(   documentation of the 1.x protocol is contained in README files that) s
+5 624 M
+(   are shipped along with the source code.) s
+5 602 M
+(4.3.1 Old Client, New Server) s
+5 580 M
+(   Server implementations MAY support a configurable "compatibility") s
+5 569 M
+(   flag that enables compatibility with old versions.  When this flag is) s
+5 558 M
+(   on, the server SHOULD identify its protocol version as "1.99".) s
+5 547 M
+(   Clients using protocol 2.0 MUST be able to identify this as identical) s
+5 536 M
+(   to "2.0".  In this mode the server SHOULD NOT send the carriage) s
+5 525 M
+(   return character \(ASCII 13\) after the version identification string.) s
+5 503 M
+(   In the compatibility mode the server SHOULD NOT send any further data) s
+5 492 M
+(   after its initialization string until it has received an) s
+5 481 M
+(   identification string from the client.  The server can then determine) s
+5 470 M
+(   whether the client is using an old protocol, and can revert to the) s
+5 459 M
+(   old protocol if required.  In the compatibility mode, the server MUST) s
+5 448 M
+(   NOT send additional data before the version string.) s
+5 426 M
+(   When compatibility with old clients is not needed, the server MAY) s
+5 415 M
+(   send its initial key exchange data immediately after the) s
+5 404 M
+(   identification string.) s
+5 382 M
+(4.3.2 New Client, Old Server) s
+5 360 M
+(   Since the new client MAY immediately send additional data after its) s
+5 349 M
+(   identification string \(before receiving server's identification\), the) s
+5 338 M
+(   old protocol may already have been corrupted when the client learns) s
+5 327 M
+(   that the server is old.  When this happens, the client SHOULD close) s
+5 316 M
+(   the connection to the server, and reconnect using the old protocol.) s
+5 294 M
+(5. Binary Packet Protocol) s
+5 272 M
+(   Each packet is in the following format:) s
+5 250 M
+(     uint32    packet_length) s
+5 239 M
+(     byte      padding_length) s
+5 228 M
+(     byte[n1]  payload; n1 = packet_length - padding_length - 1) s
+5 217 M
+(     byte[n2]  random padding; n2 = padding_length) s
+5 206 M
+(     byte[m]   mac \(message authentication code\); m = mac_length) s
+5 184 M
+(      packet_length) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 5]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 6 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(         The length of the packet \(bytes\), not including MAC or the) s
+5 679 M
+(         packet_length field itself.) s
+5 657 M
+(      padding_length) s
+5 646 M
+(         Length of padding \(bytes\).) s
+5 624 M
+(      payload) s
+5 613 M
+(         The useful contents of the packet.  If compression has been) s
+5 602 M
+(         negotiated, this field is compressed.  Initially, compression) s
+5 591 M
+(         MUST be "none".) s
+5 569 M
+(      random padding) s
+5 558 M
+(         Arbitrary-length padding, such that the total length of) s
+5 547 M
+(         \(packet_length || padding_length || payload || padding\) is a) s
+5 536 M
+(         multiple of the cipher block size or 8, whichever is larger.) s
+5 525 M
+(         There MUST be at least four bytes of padding.  The padding) s
+5 514 M
+(         SHOULD consist of random bytes.  The maximum amount of padding) s
+5 503 M
+(         is 255 bytes.) s
+5 481 M
+(      mac) s
+5 470 M
+(         Message authentication code.  If message authentication has) s
+5 459 M
+(         been negotiated, this field contains the MAC bytes.  Initially,) s
+5 448 M
+(         the MAC algorithm MUST be "none".) s
+5 415 M
+(   Note that length of the concatenation of packet length, padding) s
+5 404 M
+(   length, payload, and padding MUST be a multiple of the cipher block) s
+5 393 M
+(   size or 8, whichever is larger.  This constraint MUST be enforced) s
+5 382 M
+(   even when using stream ciphers.  Note that the packet length field is) s
+5 371 M
+(   also encrypted, and processing it requires special care when sending) s
+5 360 M
+(   or receiving packets.) s
+5 338 M
+(   The minimum size of a packet is 16 \(or the cipher block size,) s
+5 327 M
+(   whichever is larger\) bytes \(plus MAC\); implementations SHOULD decrypt) s
+5 316 M
+(   the length after receiving the first 8 \(or cipher block size,) s
+5 305 M
+(   whichever is larger\) bytes of a packet.) s
+5 283 M
+(5.1 Maximum Packet Length) s
+5 261 M
+(   All implementations MUST be able to process packets with uncompressed) s
+5 250 M
+(   payload length of 32768 bytes or less and total packet size of 35000) s
+5 239 M
+(   bytes or less \(including length, padding length, payload, padding,) s
+5 228 M
+(   and MAC.\). The maximum of 35000 bytes is an arbitrary chosen value) s
+5 217 M
+(   larger than uncompressed size. Implementations SHOULD support longer) s
+5 206 M
+(   packets, where they might be needed, e.g. if an implementation wants) s
+5 195 M
+(   to send a very large number of certificates.  Such packets MAY be) s
+5 184 M
+(   sent if the version string indicates that the other party is able to) s
+5 173 M
+(   process them. However, implementations SHOULD check that the packet) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 6]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (6,7) 4
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 7 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(   length is reasonable for the implementation to avoid) s
+5 679 M
+(   denial-of-service and/or buffer overflow attacks.) s
+5 657 M
+(5.2 Compression) s
+5 635 M
+(   If compression has been negotiated, the payload field \(and only it\)) s
+5 624 M
+(   will be compressed using the negotiated algorithm. The length field) s
+5 613 M
+(   and MAC will be computed from the compressed payload. Encryption will) s
+5 602 M
+(   be done after compression.) s
+5 580 M
+(   Compression MAY be stateful, depending on the method. Compression) s
+5 569 M
+(   MUST be independent for each direction, and implementations MUST) s
+5 558 M
+(   allow independently choosing the algorithm for each direction.) s
+5 536 M
+(   The following compression methods are currently defined:) s
+5 514 M
+(     none     REQUIRED        no compression) s
+5 503 M
+(     zlib     OPTIONAL        ZLIB \(LZ77\) compression) s
+5 481 M
+(   The "zlib" compression is described in [RFC1950] and in [RFC1951].) s
+5 470 M
+(   The compression context is initialized after each key exchange, and) s
+5 459 M
+(   is passed from one packet to the next with only a partial flush being) s
+5 448 M
+(   performed at the end of each packet. A partial flush means that the) s
+5 437 M
+(   current compressed block is ended and all data will be output. If the) s
+5 426 M
+(   current block is not a stored block, one or more empty blocks are) s
+5 415 M
+(   added after the current block to ensure that there are at least 8) s
+5 404 M
+(   bits counting from the start of the end-of-block code of the current) s
+5 393 M
+(   block to the end of the packet payload.) s
+5 371 M
+(   Additional methods may be defined as specified in [SSH-ARCH].) s
+5 349 M
+(5.3 Encryption) s
+5 327 M
+(   An encryption algorithm and a key will be negotiated during the key) s
+5 316 M
+(   exchange.  When encryption is in effect, the packet length, padding) s
+5 305 M
+(   length, payload and padding fields of each packet MUST be encrypted) s
+5 294 M
+(   with the given algorithm.) s
+5 272 M
+(   The encrypted data in all packets sent in one direction SHOULD be) s
+5 261 M
+(   considered a single data stream.  For example, initialization vectors) s
+5 250 M
+(   SHOULD be passed from the end of one packet to the beginning of the) s
+5 239 M
+(   next packet. All ciphers SHOULD use keys with an effective key length) s
+5 228 M
+(   of 128 bits or more.) s
+5 206 M
+(   The ciphers in each direction MUST run independently of each other,) s
+5 195 M
+(   and implementations MUST allow independently choosing the algorithm) s
+5 184 M
+(   for each direction \(if multiple algorithms are allowed by local) s
+5 173 M
+(   policy\).) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 7]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 8 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(   The following ciphers are currently defined:) s
+5 668 M
+(     3des-cbc         REQUIRED          three-key 3DES in CBC mode) s
+5 657 M
+(     blowfish-cbc     OPTIONALi         Blowfish in CBC mode) s
+5 646 M
+(     twofish256-cbc   OPTIONAL          Twofish in CBC mode,) s
+5 635 M
+(                                        with 256-bit key) s
+5 624 M
+(     twofish-cbc      OPTIONAL          alias for "twofish256-cbc" \(this) s
+5 613 M
+(                                        is being retained for) s
+5 602 M
+(                                        historical reasons\)) s
+5 591 M
+(     twofish192-cbc   OPTIONAL          Twofish with 192-bit key) s
+5 580 M
+(     twofish128-cbc   OPTIONAL          Twofish with 128-bit key) s
+5 569 M
+(     aes256-cbc       OPTIONAL          AES \(Rijndael\) in CBC mode,) s
+5 558 M
+(                                        with 256-bit key) s
+5 547 M
+(     aes192-cbc       OPTIONAL          AES with 192-bit key) s
+5 536 M
+(     aes128-cbc       RECOMMENDED       AES with 128-bit key) s
+5 525 M
+(     serpent256-cbc   OPTIONAL          Serpent in CBC mode, with) s
+5 514 M
+(                                        256-bit key) s
+5 503 M
+(     serpent192-cbc   OPTIONAL          Serpent with 192-bit key) s
+5 492 M
+(     serpent128-cbc   OPTIONAL          Serpent with 128-bit key) s
+5 481 M
+(     arcfour          OPTIONAL          the ARCFOUR stream cipher) s
+5 470 M
+(     idea-cbc         OPTIONAL          IDEA in CBC mode) s
+5 459 M
+(     cast128-cbc      OPTIONAL          CAST-128 in CBC mode) s
+5 448 M
+(     none             OPTIONAL          no encryption; NOT RECOMMENDED) s
+5 426 M
+(   The "3des-cbc" cipher is three-key triple-DES) s
+5 415 M
+(   \(encrypt-decrypt-encrypt\), where the first 8 bytes of the key are) s
+5 404 M
+(   used for the first encryption, the next 8 bytes for the decryption,) s
+5 393 M
+(   and the following 8 bytes for the final encryption.  This requires 24) s
+5 382 M
+(   bytes of key data \(of which 168 bits are actually used\).  To) s
+5 371 M
+(   implement CBC mode, outer chaining MUST be used \(i.e., there is only) s
+5 360 M
+(   one initialization vector\).  This is a block cipher with 8 byte) s
+5 349 M
+(   blocks.  This algorithm is defined in [FIPS-46-3]) s
+5 327 M
+(   The "blowfish-cbc" cipher is Blowfish in CBC mode, with 128 bit keys) s
+5 316 M
+(   [SCHNEIER]. This is a block cipher with 8 byte blocks.) s
+5 294 M
+(   The "twofish-cbc" or "twofish256-cbc" cipher is Twofish in CBC mode,) s
+5 283 M
+(   with 256 bit keys as described [TWOFISH]. This is a block cipher with) s
+5 272 M
+(   16 byte blocks.) s
+5 250 M
+(   The "twofish192-cbc" cipher. Same as above but with 192-bit key.) s
+5 228 M
+(   The "twofish128-cbc" cipher. Same as above but with 128-bit key.) s
+5 206 M
+(   The "aes256-cbc" cipher is AES \(Advanced Encryption Standard\)) s
+5 195 M
+(   [FIPS-197], formerly Rijndael, in CBC mode. This version uses 256-bit) s
+5 184 M
+(   key.) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 8]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (8,9) 5
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 9 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(   The "aes192-cbc" cipher. Same as above but with 192-bit key.) s
+5 668 M
+(   The "aes128-cbc" cipher. Same as above but with 128-bit key.) s
+5 646 M
+(   The "serpent256-cbc" cipher in CBC mode, with 256-bit key as) s
+5 635 M
+(   described in the Serpent AES submission.) s
+5 613 M
+(   The "serpent192-cbc" cipher. Same as above but with 192-bit key.) s
+5 591 M
+(   The "serpent128-cbc" cipher. Same as above but with 128-bit key.) s
+5 569 M
+(   The "arcfour" is the Arcfour stream cipher with 128 bit keys. The) s
+5 558 M
+(   Arcfour cipher is believed to be compatible with the RC4 cipher) s
+5 547 M
+(   [SCHNEIER]. RC4 is a registered trademark of RSA Data Security Inc.) s
+5 536 M
+(   Arcfour \(and RC4\) has problems with weak keys, and should be used) s
+5 525 M
+(   with caution.) s
+5 503 M
+(   The "idea-cbc" cipher is the IDEA cipher in CBC mode [SCHNEIER].) s
+5 481 M
+(   The "cast128-cbc" cipher is the CAST-128 cipher in CBC mode) s
+5 470 M
+(   [RFC2144].) s
+5 448 M
+(   The "none" algorithm specifies that no encryption is to be done.) s
+5 437 M
+(   Note that this method provides no confidentiality protection, and it) s
+5 426 M
+(   is not recommended.  Some functionality \(e.g. password) s
+5 415 M
+(   authentication\) may be disabled for security reasons if this cipher) s
+5 404 M
+(   is chosen.) s
+5 382 M
+(   Additional methods may be defined as specified in [SSH-ARCH].) s
+5 360 M
+(5.4 Data Integrity) s
+5 338 M
+(   Data integrity is protected by including with each packet a message) s
+5 327 M
+(   authentication code \(MAC\) that is computed from a shared secret,) s
+5 316 M
+(   packet sequence number, and the contents of the packet.) s
+5 294 M
+(   The message authentication algorithm and key are negotiated during) s
+5 283 M
+(   key exchange.  Initially, no MAC will be in effect, and its length) s
+5 272 M
+(   MUST be zero.  After key exchange, the selected MAC will be computed) s
+5 261 M
+(   before encryption from the concatenation of packet data:) s
+5 239 M
+(     mac = MAC\(key, sequence_number || unencrypted_packet\)) s
+5 217 M
+(   where unencrypted_packet is the entire packet without MAC \(the length) s
+5 206 M
+(   fields, payload and padding\), and sequence_number is an implicit) s
+5 195 M
+(   packet sequence number represented as uint32.  The sequence number is) s
+5 184 M
+(   initialized to zero for the first packet, and is incremented after) s
+5 173 M
+(   every packet \(regardless of whether encryption or MAC is in use\).  It) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 9]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 10 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(   is never reset, even if keys/algorithms are renegotiated later.  It) s
+5 679 M
+(   wraps around to zero after every 2^32 packets. The packet sequence) s
+5 668 M
+(   number itself is not included in the packet sent over the wire.) s
+5 646 M
+(   The MAC algorithms for each direction MUST run independently, and) s
+5 635 M
+(   implementations MUST allow choosing the algorithm independently for) s
+5 624 M
+(   both directions.) s
+5 602 M
+(   The MAC bytes resulting from the MAC algorithm MUST be transmitted) s
+5 591 M
+(   without encryption as the last part of the packet.  The number of MAC) s
+5 580 M
+(   bytes depends on the algorithm chosen.) s
+5 558 M
+(   The following MAC algorithms are currently defined:) s
+5 536 M
+(     hmac-sha1    REQUIRED        HMAC-SHA1 \(digest length = key) s
+5 525 M
+(                                  length = 20\)) s
+5 514 M
+(     hmac-sha1-96 RECOMMENDED     first 96 bits of HMAC-SHA1 \(digest) s
+5 503 M
+(                                  length = 12, key length = 20\)) s
+5 492 M
+(     hmac-md5     OPTIONAL        HMAC-MD5 \(digest length = key) s
+5 481 M
+(                                  length = 16\)) s
+5 470 M
+(     hmac-md5-96  OPTIONAL        first 96 bits of HMAC-MD5 \(digest) s
+5 459 M
+(                                  length = 12, key length = 16\)) s
+5 448 M
+(     none         OPTIONAL        no MAC; NOT RECOMMENDED) s
+5 426 M
+(                                Figure 1) s
+5 404 M
+(   The "hmac-*" algorithms are described in [RFC2104] The "*-n" MACs use) s
+5 393 M
+(   only the first n bits of the resulting value.) s
+5 371 M
+(   The hash algorithms are described in [SCHNEIER].) s
+5 349 M
+(   Additional methods may be defined as specified in [SSH-ARCH].) s
+5 327 M
+(5.5 Key Exchange Methods) s
+5 305 M
+(   The key exchange method specifies how one-time session keys are) s
+5 294 M
+(   generated for encryption and for authentication, and how the server) s
+5 283 M
+(   authentication is done.) s
+5 261 M
+(   Only one REQUIRED key exchange method has been defined:) s
+5 239 M
+(     diffie-hellman-group1-sha1       REQUIRED) s
+5 217 M
+(   This method is described later in this document.) s
+5 195 M
+(   Additional methods may be defined as specified in [SSH-ARCH].) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 10]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (10,11) 6
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 11 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(5.6 Public Key Algorithms) s
+5 668 M
+(   This protocol has been designed to be able to operate with almost any) s
+5 657 M
+(   public key format, encoding, and algorithm \(signature and/or) s
+5 646 M
+(   encryption\).) s
+5 624 M
+(   There are several aspects that define a public key type:) s
+5 613 M
+(   o  Key format: how is the key encoded and how are certificates) s
+5 602 M
+(      represented.  The key blobs in this protocol MAY contain) s
+5 591 M
+(      certificates in addition to keys.) s
+5 580 M
+(   o  Signature and/or encryption algorithms.  Some key types may not) s
+5 569 M
+(      support both signing and encryption.  Key usage may also be) s
+5 558 M
+(      restricted by policy statements in e.g. certificates.  In this) s
+5 547 M
+(      case, different key types SHOULD be defined for the different) s
+5 536 M
+(      policy alternatives.) s
+5 525 M
+(   o  Encoding of signatures and/or encrypted data. This includes but is) s
+5 514 M
+(      not limited to padding, byte order, and data formats.) s
+5 492 M
+(   The following public key and/or certificate formats are currently defined:) s
+5 470 M
+(   ssh-dss              REQUIRED     sign    Raw DSS Key) s
+5 459 M
+(   ssh-rsa              RECOMMENDED  sign    Raw RSA Key) s
+5 448 M
+(   x509v3-sign-rsa      OPTIONAL     sign    X.509 certificates \(RSA key\)) s
+5 437 M
+(   x509v3-sign-dss      OPTIONAL     sign    X.509 certificates \(DSS key\)) s
+5 426 M
+(   spki-sign-rsa        OPTIONAL     sign    SPKI certificates \(RSA key\)) s
+5 415 M
+(   spki-sign-dss        OPTIONAL     sign    SPKI certificates \(DSS key\)) s
+5 404 M
+(   pgp-sign-rsa         OPTIONAL     sign    OpenPGP certificates \(RSA key\)) s
+5 393 M
+(   pgp-sign-dss         OPTIONAL     sign    OpenPGP certificates \(DSS key\)) s
+5 371 M
+(   Additional key types may be defined as specified in [SSH-ARCH].) s
+5 349 M
+(   The key type MUST always be explicitly known \(from algorithm) s
+5 338 M
+(   negotiation or some other source\).  It is not normally included in) s
+5 327 M
+(   the key blob.) s
+5 305 M
+(   Certificates and public keys are encoded as follows:) s
+5 283 M
+(     string   certificate or public key format identifier) s
+5 272 M
+(     byte[n]  key/certificate data) s
+5 250 M
+(   The certificate part may have be a zero length string, but a public) s
+5 239 M
+(   key is required. This is the public key that will be used for) s
+5 228 M
+(   authentication; the certificate sequence contained in the certificate) s
+5 217 M
+(   blob can be used to provide authorization.) s
+5 195 M
+(   Public key / certifcate formats that do not explicitly specify a) s
+5 184 M
+(   signature format identifier MUST use the public key / certificate) s
+5 173 M
+(   format identifier as the signature identifier.) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 11]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 12 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(   Signatures are encoded as follows:) s
+5 679 M
+(     string    signature format identifier \(as specified by the) s
+5 668 M
+(               public key / cert format\)) s
+5 657 M
+(     byte[n]   signature blob in format specific encoding.) s
+5 624 M
+(   The "ssh-dss" key format has the following specific encoding:) s
+5 602 M
+(     string    "ssh-dss") s
+5 591 M
+(     mpint     p) s
+5 580 M
+(     mpint     q) s
+5 569 M
+(     mpint     g) s
+5 558 M
+(     mpint     y) s
+5 536 M
+(   Here the p, q, g, and y parameters form the signature key blob.) s
+5 514 M
+(   Signing and verifying using this key format is done according to the) s
+5 503 M
+(   Digital Signature Standard [FIPS-186] using the SHA-1 hash. A) s
+5 492 M
+(   description can also be found in [SCHNEIER].) s
+5 470 M
+(   The resulting signature is encoded as follows:) s
+5 448 M
+(     string    "ssh-dss") s
+5 437 M
+(     string    dss_signature_blob) s
+5 415 M
+(   dss_signature_blob is encoded as a string containing r followed by s) s
+5 404 M
+(   \(which are 160 bits long integers, without lengths or padding,) s
+5 393 M
+(   unsigned and in network byte order\).) s
+5 371 M
+(   The "ssh-rsa" key format has the following specific encoding:) s
+5 349 M
+(     string    "ssh-rsa") s
+5 338 M
+(     mpint     e) s
+5 327 M
+(     mpint     n) s
+5 305 M
+(   Here the e and n parameters form the signature key blob.) s
+5 283 M
+(   Signing and verifying using this key format is done according to) s
+5 272 M
+(   [SCHNEIER] and [PKCS1] using the SHA-1 hash.) s
+5 250 M
+(   The resulting signature is encoded as follows:) s
+5 228 M
+(     string    "ssh-rsa") s
+5 217 M
+(     string    rsa_signature_blob) s
+5 195 M
+(   rsa_signature_blob is encoded as a string containing s \(which is an) s
+5 184 M
+(   integer, without lengths or padding, unsigned and in network byte) s
+5 173 M
+(   order\).) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 12]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (12,13) 7
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 13 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(   The "spki-sign-rsa" method indicates that the certificate blob) s
+5 679 M
+(   contains a sequence of SPKI certificates. The format of SPKI) s
+5 668 M
+(   certificates is described in [RFC2693]. This method indicates that) s
+5 657 M
+(   the key \(or one of the keys in the certificate\) is an RSA-key.) s
+5 635 M
+(   The "spki-sign-dss". As above, but indicates that the key \(or one of) s
+5 624 M
+(   the keys in the certificate\) is a DSS-key.) s
+5 602 M
+(   The "pgp-sign-rsa" method indicates the certificates, the public key,) s
+5 591 M
+(   and the signature are in OpenPGP compatible binary format) s
+5 580 M
+(   \([RFC2440]\). This method indicates that the key is an RSA-key.) s
+5 558 M
+(   The "pgp-sign-dss". As above, but indicates that the key is a) s
+5 547 M
+(   DSS-key.) s
+5 525 M
+(6. Key Exchange) s
+5 503 M
+(   Key exchange begins by each side sending lists of supported) s
+5 492 M
+(   algorithms. Each side has a preferred algorithm in each category, and) s
+5 481 M
+(   it is assumed that most implementations at any given time will use) s
+5 470 M
+(   the same preferred algorithm.  Each side MAY guess which algorithm) s
+5 459 M
+(   the other side is using, and MAY send an initial key exchange packet) s
+5 448 M
+(   according to the algorithm if appropriate for the preferred method.) s
+5 426 M
+(   Guess is considered wrong, if:) s
+5 415 M
+(   o  the kex algorithm and/or the host key algorithm is guessed wrong) s
+5 404 M
+(      \(server and client have different preferred algorithm\), or) s
+5 393 M
+(   o  if any of the other algorithms cannot be agreed upon \(the) s
+5 382 M
+(      procedure is defined below in Section Section 6.1\).) s
+5 360 M
+(   Otherwise, the guess is considered to be right and the optimistically) s
+5 349 M
+(   sent packet MUST be handled as the first key exchange packet.) s
+5 327 M
+(   However, if the guess was wrong, and a packet was optimistically sent) s
+5 316 M
+(   by one or both parties, such packets MUST be ignored \(even if the) s
+5 305 M
+(   error in the guess would not affect the contents of the initial) s
+5 294 M
+(   packet\(s\)\), and the appropriate side MUST send the correct initial) s
+5 283 M
+(   packet.) s
+5 261 M
+(   Server authentication in the key exchange MAY be implicit.  After a) s
+5 250 M
+(   key exchange with implicit server authentication, the client MUST) s
+5 239 M
+(   wait for response to its service request message before sending any) s
+5 228 M
+(   further data.) s
+5 206 M
+(6.1 Algorithm Negotiation) s
+5 184 M
+(   Key exchange begins by each side sending the following packet:) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 13]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 14 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(     byte      SSH_MSG_KEXINIT) s
+5 679 M
+(     byte[16]  cookie \(random bytes\)) s
+5 668 M
+(     string    kex_algorithms) s
+5 657 M
+(     string    server_host_key_algorithms) s
+5 646 M
+(     string    encryption_algorithms_client_to_server) s
+5 635 M
+(     string    encryption_algorithms_server_to_client) s
+5 624 M
+(     string    mac_algorithms_client_to_server) s
+5 613 M
+(     string    mac_algorithms_server_to_client) s
+5 602 M
+(     string    compression_algorithms_client_to_server) s
+5 591 M
+(     string    compression_algorithms_server_to_client) s
+5 580 M
+(     string    languages_client_to_server) s
+5 569 M
+(     string    languages_server_to_client) s
+5 558 M
+(     boolean   first_kex_packet_follows) s
+5 547 M
+(     uint32    0 \(reserved for future extension\)) s
+5 525 M
+(   Each of the algorithm strings MUST be a comma-separated list of) s
+5 514 M
+(   algorithm names \(see ''Algorithm Naming'' in [SSH-ARCH]\). Each) s
+5 503 M
+(   supported \(allowed\) algorithm MUST be listed in order of preference.) s
+5 481 M
+(   The first algorithm in each list MUST be the preferred \(guessed\)) s
+5 470 M
+(   algorithm.  Each string MUST contain at least one algorithm name.) s
+5 437 M
+(      cookie) s
+5 426 M
+(         The cookie MUST be a random value generated by the sender.  Its) s
+5 415 M
+(         purpose is to make it impossible for either side to fully) s
+5 404 M
+(         determine the keys and the session identifier.) s
+5 382 M
+(      kex_algorithms) s
+5 371 M
+(         Key exchange algorithms were defined above.  The first) s
+5 360 M
+(         algorithm MUST be the preferred \(and guessed\) algorithm.  If) s
+5 349 M
+(         both sides make the same guess, that algorithm MUST be used.) s
+5 338 M
+(         Otherwise, the following algorithm MUST be used to choose a key) s
+5 327 M
+(         exchange method: iterate over client's kex algorithms, one at a) s
+5 316 M
+(         time.  Choose the first algorithm that satisfies the following) s
+5 305 M
+(         conditions:) s
+5 294 M
+(         +  the server also supports the algorithm,) s
+5 283 M
+(         +  if the algorithm requires an encryption-capable host key,) s
+5 272 M
+(            there is an encryption-capable algorithm on the server's) s
+5 261 M
+(            server_host_key_algorithms that is also supported by the) s
+5 250 M
+(            client, and) s
+5 239 M
+(         +  if the algorithm requires a signature-capable host key,) s
+5 228 M
+(            there is a signature-capable algorithm on the server's) s
+5 217 M
+(            server_host_key_algorithms that is also supported by the) s
+5 206 M
+(            client.) s
+5 195 M
+(         +  If no algorithm satisfying all these conditions can be) s
+5 184 M
+(            found, the connection fails, and both sides MUST disconnect.) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 14]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (14,15) 8
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 15 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(      server_host_key_algorithms) s
+5 679 M
+(         List of the algorithms supported for the server host key.  The) s
+5 668 M
+(         server lists the algorithms for which it has host keys; the) s
+5 657 M
+(         client lists the algorithms that it is willing to accept.) s
+5 646 M
+(         \(There MAY be multiple host keys for a host, possibly with) s
+5 635 M
+(         different algorithms.\)) s
+5 613 M
+(         Some host keys may not support both signatures and encryption) s
+5 602 M
+(         \(this can be determined from the algorithm\), and thus not all) s
+5 591 M
+(         host keys are valid for all key exchange methods.) s
+5 569 M
+(         Algorithm selection depends on whether the chosen key exchange) s
+5 558 M
+(         algorithm requires a signature or encryption capable host key.) s
+5 547 M
+(         It MUST be possible to determine this from the public key) s
+5 536 M
+(         algorithm name.  The first algorithm on the client's list that) s
+5 525 M
+(         satisfies the requirements and is also supported by the server) s
+5 514 M
+(         MUST be chosen.  If there is no such algorithm, both sides MUST) s
+5 503 M
+(         disconnect.) s
+5 481 M
+(      encryption_algorithms) s
+5 470 M
+(         Lists the acceptable symmetric encryption algorithms in order) s
+5 459 M
+(         of preference.  The chosen encryption algorithm to each) s
+5 448 M
+(         direction MUST be the first algorithm  on the client's list) s
+5 437 M
+(         that is also on the server's list. If there is no such) s
+5 426 M
+(         algorithm, both sides MUST disconnect.) s
+5 404 M
+(         Note that "none" must be explicitly listed if it is to be) s
+5 393 M
+(         acceptable.  The defined algorithm names are listed in Section) s
+5 382 M
+(         Section 5.3.) s
+5 360 M
+(      mac_algorithms) s
+5 349 M
+(         Lists the acceptable MAC algorithms in order of preference.) s
+5 338 M
+(         The chosen MAC algorithm MUST be the first algorithm on the) s
+5 327 M
+(         client's list that is also on the server's list.  If there is) s
+5 316 M
+(         no such algorithm, both sides MUST disconnect.) s
+5 294 M
+(         Note that "none" must be explicitly listed if it is to be) s
+5 283 M
+(         acceptable.  The MAC algorithm names are listed in Section) s
+5 272 M
+(         Figure 1.) s
+5 250 M
+(      compression_algorithms) s
+5 239 M
+(         Lists the acceptable compression algorithms in order of) s
+5 228 M
+(         preference. The chosen compression algorithm MUST be the first) s
+5 217 M
+(         algorithm on the client's list that is also on the server's) s
+5 206 M
+(         list.  If there is no such algorithm, both sides MUST) s
+5 195 M
+(         disconnect.) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 15]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 16 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(         Note that "none" must be explicitly listed if it is to be) s
+5 679 M
+(         acceptable.  The compression algorithm names are listed in) s
+5 668 M
+(         Section Section 5.2.) s
+5 646 M
+(      languages) s
+5 635 M
+(         This is a comma-separated list of language tags in order of) s
+5 624 M
+(         preference [RFC3066]. Both parties MAY ignore this list. If) s
+5 613 M
+(         there are no language preferences, this list SHOULD be empty.) s
+5 602 M
+(         Language tags SHOULD NOT be present unless they are known to be) s
+5 591 M
+(         needed by the sending party.) s
+5 569 M
+(      first_kex_packet_follows) s
+5 558 M
+(         Indicates whether a guessed key exchange packet follows.  If a) s
+5 547 M
+(         guessed packet will be sent, this MUST be TRUE.  If no guessed) s
+5 536 M
+(         packet will be sent, this MUST be FALSE.) s
+5 514 M
+(         After receiving the SSH_MSG_KEXINIT packet from the other side,) s
+5 503 M
+(         each party will know whether their guess was right.  If the) s
+5 492 M
+(         other party's guess was wrong, and this field was TRUE, the) s
+5 481 M
+(         next packet MUST be silently ignored, and both sides MUST then) s
+5 470 M
+(         act as determined by the negotiated key exchange method.  If) s
+5 459 M
+(         the guess was right, key exchange MUST continue using the) s
+5 448 M
+(         guessed packet.) s
+5 426 M
+(   After the KEXINIT packet exchange, the key exchange algorithm is run.) s
+5 415 M
+(   It may involve several packet exchanges, as specified by the key) s
+5 404 M
+(   exchange method.) s
+5 382 M
+(6.2 Output from Key Exchange) s
+5 360 M
+(   The key exchange produces two values: a shared secret K, and an) s
+5 349 M
+(   exchange hash H.  Encryption and authentication keys are derived from) s
+5 338 M
+(   these. The exchange hash H from the first key exchange is) s
+5 327 M
+(   additionally used as the session identifier, which is a unique) s
+5 316 M
+(   identifier for this connection.  It is used by authentication methods) s
+5 305 M
+(   as a part of the data that is signed as a proof of possession of a) s
+5 294 M
+(   private key.  Once computed, the session identifier is not changed,) s
+5 283 M
+(   even if keys are later re-exchanged.) s
+5 250 M
+(   Each key exchange method specifies a hash function that is used in) s
+5 239 M
+(   the key exchange.  The same hash algorithm MUST be used in key) s
+5 228 M
+(   derivation. Here, we'll call it HASH.) s
+5 195 M
+(   Encryption keys MUST be computed as HASH of a known value and K as) s
+5 184 M
+(   follows:) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 16]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (16,17) 9
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 17 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(   o  Initial IV client to server: HASH\(K || H || "A" || session_id\)) s
+5 679 M
+(      \(Here K is encoded as mpint and "A" as byte and session_id as raw) s
+5 668 M
+(      data."A" means the single character A, ASCII 65\).) s
+5 657 M
+(   o  Initial IV server to client: HASH\(K || H || "B" || session_id\)) s
+5 646 M
+(   o  Encryption key client to server: HASH\(K || H || "C" || session_id\)) s
+5 635 M
+(   o  Encryption key server to client: HASH\(K || H || "D" || session_id\)) s
+5 624 M
+(   o  Integrity key client to server: HASH\(K || H || "E" || session_id\)) s
+5 613 M
+(   o  Integrity key server to client: HASH\(K || H || "F" || session_id\)) s
+5 591 M
+(   Key data MUST be taken from the beginning of the hash output. 128) s
+5 580 M
+(   bits \(16 bytes\) MUST be used for algorithms with variable-length) s
+5 569 M
+(   keys. The only variable key length algorithm defined in this document) s
+5 558 M
+(   is arcfour\).  For other algorithms, as many bytes as are needed are) s
+5 547 M
+(   taken from the beginning of the hash value. If the key length needed) s
+5 536 M
+(   is longer than the output of the HASH, the key is extended by) s
+5 525 M
+(   computing HASH of the concatenation of K and H and the entire key so) s
+5 514 M
+(   far, and appending the resulting bytes \(as many as HASH generates\) to) s
+5 503 M
+(   the key.  This process is repeated until enough key material is) s
+5 492 M
+(   available; the key is taken from the beginning of this value. In) s
+5 481 M
+(   other words:) s
+5 459 M
+(     K1 = HASH\(K || H || X || session_id\)   \(X is e.g. "A"\)) s
+5 448 M
+(     K2 = HASH\(K || H || K1\)) s
+5 437 M
+(     K3 = HASH\(K || H || K1 || K2\)) s
+5 426 M
+(     ...) s
+5 415 M
+(     key = K1 || K2 || K3 || ...) s
+5 393 M
+(   This process will lose entropy if the amount of entropy in K is) s
+5 382 M
+(   larger than the internal state size of HASH.) s
+5 360 M
+(6.3 Taking Keys Into Use) s
+5 338 M
+(   Key exchange ends by each side sending an SSH_MSG_NEWKEYS message.) s
+5 327 M
+(   This message is sent with the old keys and algorithms.  All messages) s
+5 316 M
+(   sent after this message MUST use the new keys and algorithms.) s
+5 283 M
+(   When this message is received, the new keys and algorithms MUST be) s
+5 272 M
+(   taken into use for receiving.) s
+5 239 M
+(   This message is the only valid message after key exchange, in) s
+5 228 M
+(   addition to SSH_MSG_DEBUG, SSH_MSG_DISCONNECT and SSH_MSG_IGNORE) s
+5 217 M
+(   messages. The purpose of this message is to ensure that a party is) s
+5 206 M
+(   able to respond with a disconnect message that the other party can) s
+5 195 M
+(   understand if something goes wrong with the key exchange.) s
+5 184 M
+(   Implementations MUST NOT accept any other messages after key exchange) s
+5 173 M
+(   before receiving SSH_MSG_NEWKEYS.) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 17]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 18 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(     byte      SSH_MSG_NEWKEYS) s
+5 657 M
+(7. Diffie-Hellman Key Exchange) s
+5 635 M
+(   The Diffie-Hellman key exchange provides a shared secret that can not) s
+5 624 M
+(   be determined by either party alone. The key exchange is combined) s
+5 613 M
+(   with a signature with the host key to provide host authentication.) s
+5 580 M
+(   In the following description \(C is the client, S is the server; p is) s
+5 569 M
+(   a large safe prime, g is a generator for a subgroup of GF\(p\), and q) s
+5 558 M
+(   is the order of the subgroup; V_S is S's version string; V_C is C's) s
+5 547 M
+(   version string; K_S is S's public host key; I_C is C's KEXINIT) s
+5 536 M
+(   message and I_S S's KEXINIT message which have been exchanged before) s
+5 525 M
+(   this part begins\):) s
+5 492 M
+(   1.  C generates a random number x \(1 < x < q\) and computes e = g^x) s
+5 481 M
+(       mod p.  C sends "e" to S.) s
+5 459 M
+(   2.  S generates a random number y \(0 < y < q\) and computes f = g^y) s
+5 448 M
+(       mod p.  S receives "e".  It computes K = e^y mod p, H = hash\(V_C) s
+5 437 M
+(       || V_S || I_C || I_S || K_S || e || f || K\) \(these elements are) s
+5 426 M
+(       encoded according to their types; see below\), and signature s on) s
+5 415 M
+(       H with its private host key. S sends "K_S || f || s" to C. The) s
+5 404 M
+(       signing operation may involve a second hashing operation.) s
+5 382 M
+(   3.  C verifies that K_S really is the host key for S \(e.g. using) s
+5 371 M
+(       certificates or a local database\). C is also allowed to accept) s
+5 360 M
+(       the key without verification; however, doing so will render the) s
+5 349 M
+(       protocol insecure against active attacks \(but may be desirable) s
+5 338 M
+(       for practical reasons in the short term in many environments\).  C) s
+5 327 M
+(       then computes K = f^x mod p, H = hash\(V_C || V_S || I_C || I_S ||) s
+5 316 M
+(       K_S || e || f || K\), and verifies the signature s on H.) s
+5 294 M
+(   Either side MUST NOT send or accept e or f values that are not in the) s
+5 283 M
+(   range [1, p-1]. If this condition is violated, the key exchange) s
+5 272 M
+(   fails.) s
+5 239 M
+(   This is implemented with the following messages.  The hash algorithm) s
+5 228 M
+(   for computing the exchange hash is defined by the method name, and is) s
+5 217 M
+(   called HASH.  The public key algorithm for signing is negotiated with) s
+5 206 M
+(   the KEXINIT messages.) s
+5 184 M
+(   First, the client sends the following:) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 18]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (18,19) 10
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 19 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(     byte      SSH_MSG_KEXDH_INIT) s
+5 679 M
+(     mpint     e) s
+5 646 M
+(   The server responds with the following:) s
+5 624 M
+(     byte      SSH_MSG_KEXDH_REPLY) s
+5 613 M
+(     string    server public host key and certificates \(K_S\)) s
+5 602 M
+(     mpint     f) s
+5 591 M
+(     string    signature of H) s
+5 569 M
+(   The hash H is computed as the HASH hash of the concatenation of the) s
+5 558 M
+(   following:) s
+5 536 M
+(     string    V_C, the client's version string \(CR and NL excluded\)) s
+5 525 M
+(     string    V_S, the server's version string \(CR and NL excluded\)) s
+5 514 M
+(     string    I_C, the payload of the client's SSH_MSG_KEXINIT) s
+5 503 M
+(     string    I_S, the payload of the server's SSH_MSG_KEXINIT) s
+5 492 M
+(     string    K_S, the host key) s
+5 481 M
+(     mpint     e, exchange value sent by the client) s
+5 470 M
+(     mpint     f, exchange value sent by the server) s
+5 459 M
+(     mpint     K, the shared secret) s
+5 437 M
+(   This value is called the exchange hash, and it is used to) s
+5 426 M
+(   authenticate the key exchange. The exchange hash SHOULD be kept) s
+5 415 M
+(   secret.) s
+5 382 M
+(   The signature algorithm MUST be applied over H, not the original) s
+5 371 M
+(   data.  Most signature algorithms include hashing and additional) s
+5 360 M
+(   padding.  For example, "ssh-dss" specifies SHA-1 hashing; in that) s
+5 349 M
+(   case, the data is first hashed with HASH to compute H, and H is then) s
+5 338 M
+(   hashed with SHA-1 as part of the signing operation.) s
+5 316 M
+(7.1 diffie-hellman-group1-sha1) s
+5 294 M
+(   The "diffie-hellman-group1-sha1" method specifies Diffie-Hellman key) s
+5 283 M
+(   exchange with SHA-1 as HASH, and Oakley group 14 [RFC3526] \(2048-bit) s
+5 272 M
+(   MODP Group\).  It is included below in hexadecimal and decimal.) s
+5 250 M
+(   The prime p is equal to 2^1024 - 2^960 - 1 + 2^64 * floor\( 2^894 Pi +) s
+5 239 M
+(   129093 \). Its hexadecimal value is:) s
+5 217 M
+(         FFFFFFFF FFFFFFFF C90FDAA2 2168C234 C4C6628B 80DC1CD1) s
+5 206 M
+(         29024E08 8A67CC74 020BBEA6 3B139B22 514A0879 8E3404DD) s
+5 195 M
+(         EF9519B3 CD3A431B 302B0A6D F25F1437 4FE1356D 6D51C245) s
+5 184 M
+(         E485B576 625E7EC6 F44C42E9 A637ED6B 0BFF5CB6 F406B7ED) s
+5 173 M
+(         EE386BFB 5A899FA5 AE9F2411 7C4B1FE6 49286651 ECE65381) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 19]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 20 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(         FFFFFFFF FFFFFFFF.) s
+5 668 M
+(   In decimal, this value is:) s
+5 646 M
+(         179769313486231590770839156793787453197860296048756011706444) s
+5 635 M
+(         423684197180216158519368947833795864925541502180565485980503) s
+5 624 M
+(         646440548199239100050792877003355816639229553136239076508735) s
+5 613 M
+(         759914822574862575007425302077447712589550957937778424442426) s
+5 602 M
+(         617334727629299387668709205606050270810842907692932019128194) s
+5 591 M
+(         467627007.) s
+5 569 M
+(   The generator used with this prime is g = 2. The group order q is \(p) s
+5 558 M
+(   - 1\) / 2.) s
+5 536 M
+(8. Key Re-Exchange) s
+5 514 M
+(   Key re-exchange is started by sending an SSH_MSG_KEXINIT packet when) s
+5 503 M
+(   not already doing a key exchange \(as described in Section Section) s
+5 492 M
+(   6.1\). When this message is received, a party MUST respond with its) s
+5 481 M
+(   own SSH_MSG_KEXINIT message except when the received SSH_MSG_KEXINIT) s
+5 470 M
+(   already was a reply. Either party MAY initiate the re-exchange, but) s
+5 459 M
+(   roles MUST NOT be changed \(i.e., the server remains the server, and) s
+5 448 M
+(   the client remains the client\).) s
+5 415 M
+(   Key re-exchange is performed using whatever encryption was in effect) s
+5 404 M
+(   when the exchange was started.  Encryption, compression, and MAC) s
+5 393 M
+(   methods are not changed before a new SSH_MSG_NEWKEYS is sent after) s
+5 382 M
+(   the key exchange \(as in the initial key exchange\).  Re-exchange is) s
+5 371 M
+(   processed identically to the initial key exchange, except for the) s
+5 360 M
+(   session identifier that will remain unchanged. It is permissible to) s
+5 349 M
+(   change some or all of the algorithms during the re-exchange.  Host) s
+5 338 M
+(   keys can also change.  All keys and initialization vectors are) s
+5 327 M
+(   recomputed after the exchange.  Compression and encryption contexts) s
+5 316 M
+(   are reset.) s
+5 283 M
+(   It is recommended that the keys are changed after each gigabyte of) s
+5 272 M
+(   transmitted data or after each hour of connection time, whichever) s
+5 261 M
+(   comes sooner. However, since the re-exchange is a public key) s
+5 250 M
+(   operation, it requires a fair amount of processing power and should) s
+5 239 M
+(   not be performed too often.) s
+5 206 M
+(   More application data may be sent after the SSH_MSG_NEWKEYS packet) s
+5 195 M
+(   has been sent; key exchange does not affect the protocols that lie) s
+5 184 M
+(   above the SSH transport layer.) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 20]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (20,21) 11
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 21 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(9. Service Request) s
+5 668 M
+(   After the key exchange, the client requests a service. The service is) s
+5 657 M
+(   identified by a name. The format of names and procedures for defining) s
+5 646 M
+(   new names are defined in [SSH-ARCH].) s
+5 613 M
+(   Currently, the following names have been reserved:) s
+5 591 M
+(     ssh-userauth) s
+5 580 M
+(     ssh-connection) s
+5 558 M
+(   Similar local naming policy is applied to the service names, as is) s
+5 547 M
+(   applied to the algorithm names; a local service should use the) s
+5 536 M
+(   "servicename@domain" syntax.) s
+5 514 M
+(     byte      SSH_MSG_SERVICE_REQUEST) s
+5 503 M
+(     string    service name) s
+5 481 M
+(   If the server rejects the service request, it SHOULD send an) s
+5 470 M
+(   appropriate SSH_MSG_DISCONNECT message and MUST disconnect.) s
+5 437 M
+(   When the service starts, it may have access to the session identifier) s
+5 426 M
+(   generated during the key exchange.) s
+5 393 M
+(   If the server supports the service \(and permits the client to use) s
+5 382 M
+(   it\), it MUST respond with the following:) s
+5 360 M
+(     byte      SSH_MSG_SERVICE_ACCEPT) s
+5 349 M
+(     string    service name) s
+5 327 M
+(   Message numbers used by services should be in the area reserved for) s
+5 316 M
+(   them \(see Section 6 in [SSH-ARCH]\).  The transport level will) s
+5 305 M
+(   continue to process its own messages.) s
+5 272 M
+(   Note that after a key exchange with implicit server authentication,) s
+5 261 M
+(   the client MUST wait for response to its service request message) s
+5 250 M
+(   before sending any further data.) s
+5 228 M
+(10. Additional Messages) s
+5 206 M
+(   Either party may send any of the following messages at any time.) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 21]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 22 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(10.1 Disconnection Message) s
+5 668 M
+(     byte      SSH_MSG_DISCONNECT) s
+5 657 M
+(     uint32    reason code) s
+5 646 M
+(     string    description [RFC2279]) s
+5 635 M
+(     string    language tag [RFC3066]) s
+5 613 M
+(   This message causes immediate termination of the connection.  All) s
+5 602 M
+(   implementations MUST be able to process this message; they SHOULD be) s
+5 591 M
+(   able to send this message.) s
+5 569 M
+(   The sender MUST NOT send or receive any data after this message, and) s
+5 558 M
+(   the recipient MUST NOT accept any data after receiving this message.) s
+5 547 M
+(   The description field gives a more specific explanation in a) s
+5 536 M
+(   human-readable form.  The error code gives the reason in a more) s
+5 525 M
+(   machine-readable format \(suitable for localization\), and can have the) s
+5 514 M
+(   following values:) s
+5 492 M
+(     #define SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT      1) s
+5 481 M
+(     #define SSH_DISCONNECT_PROTOCOL_ERROR                   2) s
+5 470 M
+(     #define SSH_DISCONNECT_KEY_EXCHANGE_FAILED              3) s
+5 459 M
+(     #define SSH_DISCONNECT_RESERVED                         4) s
+5 448 M
+(     #define SSH_DISCONNECT_MAC_ERROR                        5) s
+5 437 M
+(     #define SSH_DISCONNECT_COMPRESSION_ERROR                6) s
+5 426 M
+(     #define SSH_DISCONNECT_SERVICE_NOT_AVAILABLE            7) s
+5 415 M
+(     #define SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED   8) s
+5 404 M
+(     #define SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE          9) s
+5 393 M
+(     #define SSH_DISCONNECT_CONNECTION_LOST                 10) s
+5 382 M
+(     #define SSH_DISCONNECT_BY_APPLICATION                  11) s
+5 371 M
+(     #define SSH_DISCONNECT_TOO_MANY_CONNECTIONS            12) s
+5 360 M
+(     #define SSH_DISCONNECT_AUTH_CANCELLED_BY_USER          13) s
+5 349 M
+(     #define SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE  14) s
+5 338 M
+(     #define SSH_DISCONNECT_ILLEGAL_USER_NAME               15) s
+5 316 M
+(   If the description string is displayed, control character filtering) s
+5 305 M
+(   discussed in [SSH-ARCH] should be used to avoid attacks by sending) s
+5 294 M
+(   terminal control characters.) s
+5 272 M
+(10.2 Ignored Data Message) s
+5 250 M
+(     byte      SSH_MSG_IGNORE) s
+5 239 M
+(     string    data) s
+5 217 M
+(   All implementations MUST understand \(and ignore\) this message at any) s
+5 206 M
+(   time \(after receiving the protocol version\). No implementation is) s
+5 195 M
+(   required to send them. This message can be used as an additional) s
+5 184 M
+(   protection measure against advanced traffic analysis techniques.) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 22]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (22,23) 12
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 23 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(10.3 Debug Message) s
+5 668 M
+(     byte      SSH_MSG_DEBUG) s
+5 657 M
+(     boolean   always_display) s
+5 646 M
+(     string    message [RFC2279]) s
+5 635 M
+(     string    language tag [RFC3066]) s
+5 613 M
+(   All implementations MUST understand this message, but they are) s
+5 602 M
+(   allowed to ignore it.  This message is used to pass the other side) s
+5 591 M
+(   information that may help debugging.  If always_display is TRUE, the) s
+5 580 M
+(   message SHOULD be displayed.  Otherwise, it SHOULD NOT be displayed) s
+5 569 M
+(   unless debugging information has been explicitly requested by the) s
+5 558 M
+(   user.) s
+5 525 M
+(   The message doesn't need to contain a newline. It is, however,) s
+5 514 M
+(   allowed to consist of multiple lines separated by CRLF \(Carriage) s
+5 503 M
+(   Return - Line Feed\) pairs.) s
+5 470 M
+(   If the message string is displayed, terminal control character) s
+5 459 M
+(   filtering discussed in [SSH-ARCH] should be used to avoid attacks by) s
+5 448 M
+(   sending terminal control characters.) s
+5 426 M
+(10.4 Reserved Messages) s
+5 404 M
+(   An implementation MUST respond to all unrecognized messages with an) s
+5 393 M
+(   SSH_MSG_UNIMPLEMENTED message in the order in which the messages were) s
+5 382 M
+(   received.  Such messages MUST be otherwise ignored.  Later protocol) s
+5 371 M
+(   versions may define other meanings for these message types.) s
+5 349 M
+(     byte      SSH_MSG_UNIMPLEMENTED) s
+5 338 M
+(     uint32    packet sequence number of rejected message) s
+5 305 M
+(11. Summary of Message Numbers) s
+5 283 M
+(   The following message numbers have been defined in this protocol:) s
+5 261 M
+(     #define SSH_MSG_DISCONNECT             1) s
+5 250 M
+(     #define SSH_MSG_IGNORE                 2) s
+5 239 M
+(     #define SSH_MSG_UNIMPLEMENTED          3) s
+5 228 M
+(     #define SSH_MSG_DEBUG                  4) s
+5 217 M
+(     #define SSH_MSG_SERVICE_REQUEST        5) s
+5 206 M
+(     #define SSH_MSG_SERVICE_ACCEPT         6) s
+5 184 M
+(     #define SSH_MSG_KEXINIT                20) s
+5 173 M
+(     #define SSH_MSG_NEWKEYS                21) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 23]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 24 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(     /* Numbers 30-49 used for kex packets.) s
+5 679 M
+(        Different kex methods may reuse message numbers in) s
+5 668 M
+(        this range. */) s
+5 646 M
+(     #define SSH_MSG_KEXDH_INIT             30) s
+5 635 M
+(     #define SSH_MSG_KEXDH_REPLY            31) s
+5 602 M
+(12. IANA Considerations) s
+5 580 M
+(   This document is part of a set, the IANA considerations for the SSH) s
+5 569 M
+(   protocol as defined in [SSH-ARCH], [SSH-TRANS], [SSH-USERAUTH],) s
+5 558 M
+(   [SSH-CONNECT] are detailed in [SSH-NUMBERS].) s
+5 536 M
+(13. Security Considerations) s
+5 514 M
+(   This protocol provides a secure encrypted channel over an insecure) s
+5 503 M
+(   network.  It performs server host authentication, key exchange,) s
+5 492 M
+(   encryption, and integrity protection.  It also derives a unique) s
+5 481 M
+(   session id that may be used by higher-level protocols.) s
+5 459 M
+(   Full security considerations for this protocol are provided in) s
+5 448 M
+(   Section 8 of [SSH-ARCH]) s
+5 426 M
+(14. Intellectual Property) s
+5 404 M
+(   The IETF takes no position regarding the validity or scope of any) s
+5 393 M
+(   intellectual property or other rights that might be claimed to) s
+5 382 M
+(   pertain to the implementation or use of the technology described in) s
+5 371 M
+(   this document or the extent to which any license under such rights) s
+5 360 M
+(   might or might not be available; neither does it represent that it) s
+5 349 M
+(   has made any effort to identify any such rights. Information on the) s
+5 338 M
+(   IETF's procedures with respect to rights in standards-track and) s
+5 327 M
+(   standards-related documentation can be found in BCP-11. Copies of) s
+5 316 M
+(   claims of rights made available for publication and any assurances of) s
+5 305 M
+(   licenses to be made available, or the result of an attempt made to) s
+5 294 M
+(   obtain a general license or permission for the use of such) s
+5 283 M
+(   proprietary rights by implementers or users of this specification can) s
+5 272 M
+(   be obtained from the IETF Secretariat.) s
+5 250 M
+(   The IETF has been notified of intellectual property rights claimed in) s
+5 239 M
+(   regard to some or all of the specification contained in this) s
+5 228 M
+(   document. For more information consult the online list of claimed) s
+5 217 M
+(   rights.) s
+5 195 M
+(15. Additional Information) s
+5 173 M
+(   The current document editor is: [email protected]. Comments on) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 24]) s
+_R
+S
+PStoPSsaved restore
+%%Page: (24,25) 13
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 0.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 25 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(   this internet draft should be sent to the IETF SECSH working group,) s
+5 679 M
+(   details at: http://ietf.org/html.charters/secsh-charter.html) s
+5 657 M
+(Normative) s
+5 635 M
+(   [SSH-ARCH]) s
+5 624 M
+(              Ylonen, T., "SSH Protocol Architecture", I-D) s
+5 613 M
+(              draft-ietf-architecture-15.txt, Oct 2003.) s
+5 591 M
+(   [SSH-TRANS]) s
+5 580 M
+(              Ylonen, T., "SSH Transport Layer Protocol", I-D) s
+5 569 M
+(              draft-ietf-transport-17.txt, Oct 2003.) s
+5 547 M
+(   [SSH-USERAUTH]) s
+5 536 M
+(              Ylonen, T., "SSH Authentication Protocol", I-D) s
+5 525 M
+(              draft-ietf-userauth-18.txt, Oct 2003.) s
+5 503 M
+(   [SSH-CONNECT]) s
+5 492 M
+(              Ylonen, T., "SSH Connection Protocol", I-D) s
+5 481 M
+(              draft-ietf-connect-18.txt, Oct 2003.) s
+5 459 M
+(   [SSH-NUMBERS]) s
+5 448 M
+(              Lehtinen, S. and D. Moffat, "SSH Protocol Assigned) s
+5 437 M
+(              Numbers", I-D draft-ietf-secsh-assignednumbers-05.txt, Oct) s
+5 426 M
+(              2003.) s
+5 404 M
+(   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate) s
+5 393 M
+(              Requirement Levels", BCP 14, RFC 2119, March 1997.) s
+5 371 M
+(Informative) s
+5 349 M
+(   [FIPS-186]) s
+5 338 M
+(              Federal Information Processing Standards Publication,) s
+5 327 M
+(              "FIPS PUB 186, Digital Signature Standard", May 1994.) s
+5 305 M
+(   [FIPS-197]) s
+5 294 M
+(              NIST, "FIPS PUB 197 Advanced Encryption Standard \(AES\)",) s
+5 283 M
+(              November 2001.) s
+5 261 M
+(   [FIPS-46-3]) s
+5 250 M
+(              U.S. Dept. of Commerce, "FIPS PUB 46-3, Data Encryption) s
+5 239 M
+(              Standard \(DES\)", October 1999.) s
+5 217 M
+(   [RFC2459]  Housley, R., Ford, W., Polk, T. and D. Solo, "Internet) s
+5 206 M
+(              X.509 Public Key Infrastructure Certificate and CRL) s
+5 195 M
+(              Profile", RFC 2459, January 1999.) s
+5 173 M
+(   [RFC1034]  Mockapetris, P., "Domain names - concepts and facilities",) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 25]) s
+_R
+S
+PStoPSsaved restore
+userdict/PStoPSsaved save put
+PStoPSmatrix setmatrix
+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
+ 595.000000 0 rlineto 0 842.000000 rlineto -595.000000 0 rlineto
+ closepath}put initclip
+PStoPSxform concat
+%%BeginPageSetup
+_S
+75 0 translate
+/pagenum 26 def
+/fname () def
+/fdir () def
+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(              STD 13, RFC 1034, November 1987.) s
+5 668 M
+(   [RFC3066]  Alvestrand, H., "Tags for the Identification of) s
+5 657 M
+(              Languages", BCP 47, RFC 3066, January 2001.) s
+5 635 M
+(   [RFC1950]  Deutsch, L. and J-L. Gailly, "ZLIB Compressed Data Format) s
+5 624 M
+(              Specification version 3.3", RFC 1950, May 1996.) s
+5 602 M
+(   [RFC1951]  Deutsch, P., "DEFLATE Compressed Data Format Specification) s
+5 591 M
+(              version 1.3", RFC 1951, May 1996.) s
+5 569 M
+(   [RFC2279]  Yergeau, F., "UTF-8, a transformation format of ISO) s
+5 558 M
+(              10646", RFC 2279, January 1998.) s
+5 536 M
+(   [RFC2104]  Krawczyk, H., Bellare, M. and R. Canetti, "HMAC:) s
+5 525 M
+(              Keyed-Hashing for Message Authentication", RFC 2104,) s
+5 514 M
+(              February 1997.) s
+5 492 M
+(   [RFC2144]  Adams, C., "The CAST-128 Encryption Algorithm", RFC 2144,) s
+5 481 M
+(              May 1997.) s
+5 459 M
+(   [RFC2440]  Callas, J., Donnerhacke, L., Finney, H. and R. Thayer,) s
+5 448 M
+(              "OpenPGP Message Format", RFC 2440, November 1998.) s
+5 426 M
+(   [RFC2693]  Ellison, C., Frantz, B., Lampson, B., Rivest, R., Thomas,) s
+5 415 M
+(              B. and T. Ylonen, "SPKI Certificate Theory", RFC 2693,) s
+5 404 M
+(              September 1999.) s
+5 382 M
+(   [RFC3526]  Kivinen, T. and M. Kojo, "More Modular Exponential \(MODP\)) s
+5 371 M
+(              Diffie-Hellman groups for Internet Key Exchange \(IKE\)",) s
+5 360 M
+(              RFC 3526, May 2003.) s
+5 338 M
+(   [SCHNEIER]) s
+5 327 M
+(              Schneier, B., "Applied Cryptography Second Edition:) s
+5 316 M
+(              protocols algorithms and source in code in C", 1996.) s
+5 294 M
+(   [TWOFISH]  Schneier, B., "The Twofish Encryptions Algorithm: A) s
+5 283 M
+(              128-Bit Block Cipher, 1st Edition", March 1999.) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 26]) s
+_R
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+PStoPSsaved restore
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+/fname () def
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+/ftail () def
+/user_header_p false def
+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(Authors' Addresses) s
+5 668 M
+(   Tatu Ylonen) s
+5 657 M
+(   SSH Communications Security Corp) s
+5 646 M
+(   Fredrikinkatu 42) s
+5 635 M
+(   HELSINKI  FIN-00100) s
+5 624 M
+(   Finland) s
+5 602 M
+(   EMail: [email protected]) s
+5 569 M
+(   Darren J. Moffat \(editor\)) s
+5 558 M
+(   Sun Microsystems, Inc) s
+5 547 M
+(   17 Network Circle) s
+5 536 M
+(   Menlo Park  95025) s
+5 525 M
+(   USA) s
+5 503 M
+(   EMail: [email protected]) s
+5 481 M
+(Appendix A. Contibutors) s
+5 129 M
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+ closepath}put initclip
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+/pagenum 28 def
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+%%EndPageSetup
+5 723 M
+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(Intellectual Property Statement) s
+5 668 M
+(   The IETF takes no position regarding the validity or scope of any) s
+5 657 M
+(   intellectual property or other rights that might be claimed to) s
+5 646 M
+(   pertain to the implementation or use of the technology described in) s
+5 635 M
+(   this document or the extent to which any license under such rights) s
+5 624 M
+(   might or might not be available; neither does it represent that it) s
+5 613 M
+(   has made any effort to identify any such rights. Information on the) s
+5 602 M
+(   IETF's procedures with respect to rights in standards-track and) s
+5 591 M
+(   standards-related documentation can be found in BCP-11. Copies of) s
+5 580 M
+(   claims of rights made available for publication and any assurances of) s
+5 569 M
+(   licenses to be made available, or the result of an attempt made to) s
+5 558 M
+(   obtain a general license or permission for the use of such) s
+5 547 M
+(   proprietary rights by implementors or users of this specification can) s
+5 536 M
+(   be obtained from the IETF Secretariat.) s
+5 514 M
+(   The IETF invites any interested party to bring to its attention any) s
+5 503 M
+(   copyrights, patents or patent applications, or other proprietary) s
+5 492 M
+(   rights which may cover technology that may be required to practice) s
+5 481 M
+(   this standard. Please address the information to the IETF Executive) s
+5 470 M
+(   Director.) s
+5 448 M
+(   The IETF has been notified of intellectual property rights claimed in) s
+5 437 M
+(   regard to some or all of the specification contained in this) s
+5 426 M
+(   document. For more information consult the online list of claimed) s
+5 415 M
+(   rights.) s
+5 382 M
+(Full Copyright Statement) s
+5 360 M
+(   Copyright \(C\) The Internet Society \(2003\). All Rights Reserved.) s
+5 338 M
+(   This document and translations of it may be copied and furnished to) s
+5 327 M
+(   others, and derivative works that comment on or otherwise explain it) s
+5 316 M
+(   or assist in its implementation may be prepared, copied, published) s
+5 305 M
+(   and distributed, in whole or in part, without restriction of any) s
+5 294 M
+(   kind, provided that the above copyright notice and this paragraph are) s
+5 283 M
+(   included on all such copies and derivative works. However, this) s
+5 272 M
+(   document itself may not be modified in any way, such as by removing) s
+5 261 M
+(   the copyright notice or references to the Internet Society or other) s
+5 250 M
+(   Internet organizations, except as needed for the purpose of) s
+5 239 M
+(   developing Internet standards in which case the procedures for) s
+5 228 M
+(   copyrights defined in the Internet Standards process must be) s
+5 217 M
+(   followed, or as required to translate it into languages other than) s
+5 206 M
+(   English.) s
+5 184 M
+(   The limited permissions granted above are perpetual and will not be) s
+5 173 M
+(   revoked by the Internet Society or its successors or assignees.) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 28]) s
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+ closepath}put initclip
+/showpage{}def/copypage{}def/erasepage{}def
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+%%BeginPageSetup
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+/fname () def
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+(Internet-Draft        SSH Transport Layer Protocol              Oct 2003) s
+5 690 M
+(   This document and the information contained herein is provided on an) s
+5 679 M
+(   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING) s
+5 668 M
+(   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING) s
+5 657 M
+(   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION) s
+5 646 M
+(   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF) s
+5 635 M
+(   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.) s
+5 602 M
+(Acknowledgment) s
+5 580 M
+(   Funding for the RFC Editor function is currently provided by the) s
+5 569 M
+(   Internet Society.) s
+5 129 M
+(Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 29]) s
+_R
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+595.000000 421.271378 translate
+90 rotate
+0.706651 dup scale
+userdict/PStoPSmatrix matrix currentmatrix put
+userdict/PStoPSclip{0 0 moveto
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+ closepath}put initclip
+PStoPSxform concat
+showpage
+PStoPSsaved restore
+%%Trailer
+%%Pages: 29
+%%DocumentNeededResources: font Courier-Bold Courier 
+%%EOF
diff --git a/lib/ssh/doc/standard/draft-ietf-secsh-transport-17.txt b/lib/ssh/doc/standard/draft-ietf-secsh-transport-17.txt
new file mode 100644
index 0000000000..9073ea52b2
--- /dev/null
+++ b/lib/ssh/doc/standard/draft-ietf-secsh-transport-17.txt
@@ -0,0 +1,1624 @@
+
+
+
+Network Working Group                                          T. Ylonen
+Internet-Draft                          SSH Communications Security Corp
+Expires: March 31, 2004                           D. Moffat, Editor, Ed.
+                                                   Sun Microsystems, Inc
+                                                                Oct 2003
+
+
+                      SSH Transport Layer Protocol
+                   draft-ietf-secsh-transport-17.txt
+
+Status of this Memo
+
+   This document is an Internet-Draft and is in full conformance with
+   all provisions of Section 10 of RFC2026.
+
+   Internet-Drafts are working documents of the Internet Engineering
+   Task Force (IETF), its areas, and its working groups. Note that other
+   groups may also distribute working documents as Internet-Drafts.
+
+   Internet-Drafts are draft documents valid for a maximum of six months
+   and may be updated, replaced, or obsoleted by other documents at any
+   time. It is inappropriate to use Internet-Drafts as reference
+   material or to cite them other than as "work in progress."
+
+   The list of current Internet-Drafts can be accessed at http://
+   www.ietf.org/ietf/1id-abstracts.txt.
+
+   The list of Internet-Draft Shadow Directories can be accessed at
+   http://www.ietf.org/shadow.html.
+
+   This Internet-Draft will expire on March 31, 2004.
+
+Copyright Notice
+
+   Copyright (C) The Internet Society (2003). All Rights Reserved.
+
+Abstract
+
+   SSH is a protocol for secure remote login and other secure network
+   services over an insecure network.
+
+   This document describes the SSH transport layer protocol which
+   typically runs on top of TCP/IP. The protocol can be used as a basis
+   for a number of secure network services. It provides strong
+   encryption, server authentication, and integrity protection. It may
+   also provide compression.
+
+   Key exchange method, public key algorithm, symmetric encryption
+   algorithm, message authentication algorithm, and hash algorithm are
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 1]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+   all negotiated.
+
+   This document also describes the Diffie-Hellman key exchange method
+   and the minimal set of algorithms that are needed to implement the
+   SSH transport layer protocol.
+
+Table of Contents
+
+   1.    Contributors . . . . . . . . . . . . . . . . . . . . . . . .  3
+   2.    Introduction . . . . . . . . . . . . . . . . . . . . . . . .  3
+   3.    Conventions Used in This Document  . . . . . . . . . . . . .  3
+   4.    Connection Setup . . . . . . . . . . . . . . . . . . . . . .  3
+   4.1   Use over TCP/IP  . . . . . . . . . . . . . . . . . . . . . .  4
+   4.2   Protocol Version Exchange  . . . . . . . . . . . . . . . . .  4
+   4.3   Compatibility With Old SSH Versions  . . . . . . . . . . . .  4
+   4.3.1 Old Client, New Server . . . . . . . . . . . . . . . . . . .  5
+   4.3.2 New Client, Old Server . . . . . . . . . . . . . . . . . . .  5
+   5.    Binary Packet Protocol . . . . . . . . . . . . . . . . . . .  5
+   5.1   Maximum Packet Length  . . . . . . . . . . . . . . . . . . .  6
+   5.2   Compression  . . . . . . . . . . . . . . . . . . . . . . . .  7
+   5.3   Encryption . . . . . . . . . . . . . . . . . . . . . . . . .  7
+   5.4   Data Integrity . . . . . . . . . . . . . . . . . . . . . . .  9
+   5.5   Key Exchange Methods . . . . . . . . . . . . . . . . . . . . 10
+   5.6   Public Key Algorithms  . . . . . . . . . . . . . . . . . . . 11
+   6.    Key Exchange . . . . . . . . . . . . . . . . . . . . . . . . 13
+   6.1   Algorithm Negotiation  . . . . . . . . . . . . . . . . . . . 13
+   6.2   Output from Key Exchange . . . . . . . . . . . . . . . . . . 16
+   6.3   Taking Keys Into Use . . . . . . . . . . . . . . . . . . . . 17
+   7.    Diffie-Hellman Key Exchange  . . . . . . . . . . . . . . . . 18
+   7.1   diffie-hellman-group1-sha1 . . . . . . . . . . . . . . . . . 19
+   8.    Key Re-Exchange  . . . . . . . . . . . . . . . . . . . . . . 20
+   9.    Service Request  . . . . . . . . . . . . . . . . . . . . . . 21
+   10.   Additional Messages  . . . . . . . . . . . . . . . . . . . . 21
+   10.1  Disconnection Message  . . . . . . . . . . . . . . . . . . . 22
+   10.2  Ignored Data Message . . . . . . . . . . . . . . . . . . . . 22
+   10.3  Debug Message  . . . . . . . . . . . . . . . . . . . . . . . 23
+   10.4  Reserved Messages  . . . . . . . . . . . . . . . . . . . . . 23
+   11.   Summary of Message Numbers . . . . . . . . . . . . . . . . . 23
+   12.   IANA Considerations  . . . . . . . . . . . . . . . . . . . . 24
+   13.   Security Considerations  . . . . . . . . . . . . . . . . . . 24
+   14.   Intellectual Property  . . . . . . . . . . . . . . . . . . . 24
+   15.   Additional Information . . . . . . . . . . . . . . . . . . . 24
+         Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 26
+         Normative  . . . . . . . . . . . . . . . . . . . . . . . . . 25
+         Informative  . . . . . . . . . . . . . . . . . . . . . . . . 25
+   A.    Contibutors  . . . . . . . . . . . . . . . . . . . . . . . . 27
+         Intellectual Property and Copyright Statements . . . . . . . 28
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 2]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+1. Contributors
+
+   The major original contributors of this document were: Tatu Ylonen,
+   Tero Kivinen, Timo J. Rinne, Sami Lehtinen (all of SSH Communications
+   Security Corp), and Markku-Juhani O. Saarinen (University of
+   Jyvaskyla)
+
+   The document editor is: [email protected].  Comments on this
+   internet draft should be sent to the IETF SECSH working group,
+   details at: http://ietf.org/html.charters/secsh-charter.html
+
+2. Introduction
+
+   The SSH transport layer is a secure low level transport protocol. It
+   provides strong encryption, cryptographic host authentication, and
+   integrity protection.
+
+   Authentication in this protocol level is host-based; this protocol
+   does not perform user authentication. A higher level protocol for
+   user authentication can be designed on top of this protocol.
+
+   The protocol has been designed to be simple, flexible, to allow
+   parameter negotiation, and to minimize the number of round-trips.
+   Key exchange method, public key algorithm, symmetric encryption
+   algorithm, message authentication algorithm, and hash algorithm are
+   all negotiated.  It is expected that in most environments, only 2
+   round-trips will be needed for full key exchange, server
+   authentication, service request, and acceptance notification of
+   service request.  The worst case is 3 round-trips.
+
+3. Conventions Used in This Document
+
+   The keywords "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT",
+   and "MAY" that appear in this document are to be interpreted as
+   described in [RFC2119].
+
+   The used data types and terminology are specified in the architecture
+   document [SSH-ARCH].
+
+   The architecture document also discusses the algorithm naming
+   conventions that MUST be used with the SSH protocols.
+
+4. Connection Setup
+
+   SSH works over any 8-bit clean, binary-transparent transport.  The
+   underlying transport SHOULD protect against transmission errors as
+   such errors cause the SSH connection to terminate.
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 3]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+   The client initiates the connection.
+
+4.1 Use over TCP/IP
+
+   When used over TCP/IP, the server normally listens for connections on
+   port 22.  This port number has been registered with the IANA, and has
+   been officially assigned for SSH.
+
+4.2 Protocol Version Exchange
+
+   When the connection has been established, both sides MUST send an
+   identification string of the form "SSH-protoversion-softwareversion
+   comments", followed by carriage return and newline characters (ASCII
+   13 and 10, respectively).  Both sides MUST be able to process
+   identification strings without carriage return character.  No null
+   character is sent.  The maximum length of the string is 255
+   characters, including the carriage return and newline.
+
+   The part of the identification string preceding carriage return and
+   newline is used in the Diffie-Hellman key exchange (see Section
+   Section 7).
+
+   The server MAY send other lines of data before sending the version
+   string.  Each line SHOULD be terminated by a carriage return and
+   newline.  Such lines MUST NOT begin with "SSH-", and SHOULD be
+   encoded in ISO-10646 UTF-8 [RFC2279] (language is not specified).
+   Clients MUST be able to process such lines; they MAY be silently
+   ignored, or MAY be displayed to the client user; if they are
+   displayed, control character filtering discussed in [SSH-ARCH] SHOULD
+   be used.  The primary use of this feature is to allow TCP-wrappers to
+   display an error message before disconnecting.
+
+   Version strings MUST consist of printable US-ASCII characters, not
+   including whitespaces or a minus sign (-).  The version string is
+   primarily used to trigger compatibility extensions and to indicate
+   the capabilities of an implementation. The comment string should
+   contain additional information that might be useful in solving user
+   problems.
+
+   The protocol version described in this document is 2.0.
+
+   Key exchange will begin immediately after sending this identifier.
+   All packets following the identification string SHALL use the binary
+   packet protocol, to be described below.
+
+4.3 Compatibility With Old SSH Versions
+
+   During the transition period, it is important to be able to work in a
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 4]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+   way that is compatible with the installed SSH clients and servers
+   that use an older version of the protocol.  Information in this
+   section is only relevant for implementations supporting compatibility
+   with SSH versions 1.x.  There is no standards track or informational
+   draft available that defines the SSH 1.x protocol.  The only known
+   documentation of the 1.x protocol is contained in README files that
+   are shipped along with the source code.
+
+4.3.1 Old Client, New Server
+
+   Server implementations MAY support a configurable "compatibility"
+   flag that enables compatibility with old versions.  When this flag is
+   on, the server SHOULD identify its protocol version as "1.99".
+   Clients using protocol 2.0 MUST be able to identify this as identical
+   to "2.0".  In this mode the server SHOULD NOT send the carriage
+   return character (ASCII 13) after the version identification string.
+
+   In the compatibility mode the server SHOULD NOT send any further data
+   after its initialization string until it has received an
+   identification string from the client.  The server can then determine
+   whether the client is using an old protocol, and can revert to the
+   old protocol if required.  In the compatibility mode, the server MUST
+   NOT send additional data before the version string.
+
+   When compatibility with old clients is not needed, the server MAY
+   send its initial key exchange data immediately after the
+   identification string.
+
+4.3.2 New Client, Old Server
+
+   Since the new client MAY immediately send additional data after its
+   identification string (before receiving server's identification), the
+   old protocol may already have been corrupted when the client learns
+   that the server is old.  When this happens, the client SHOULD close
+   the connection to the server, and reconnect using the old protocol.
+
+5. Binary Packet Protocol
+
+   Each packet is in the following format:
+
+     uint32    packet_length
+     byte      padding_length
+     byte[n1]  payload; n1 = packet_length - padding_length - 1
+     byte[n2]  random padding; n2 = padding_length
+     byte[m]   mac (message authentication code); m = mac_length
+
+      packet_length
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 5]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+         The length of the packet (bytes), not including MAC or the
+         packet_length field itself.
+
+      padding_length
+         Length of padding (bytes).
+
+      payload
+         The useful contents of the packet.  If compression has been
+         negotiated, this field is compressed.  Initially, compression
+         MUST be "none".
+
+      random padding
+         Arbitrary-length padding, such that the total length of
+         (packet_length || padding_length || payload || padding) is a
+         multiple of the cipher block size or 8, whichever is larger.
+         There MUST be at least four bytes of padding.  The padding
+         SHOULD consist of random bytes.  The maximum amount of padding
+         is 255 bytes.
+
+      mac
+         Message authentication code.  If message authentication has
+         been negotiated, this field contains the MAC bytes.  Initially,
+         the MAC algorithm MUST be "none".
+
+
+   Note that length of the concatenation of packet length, padding
+   length, payload, and padding MUST be a multiple of the cipher block
+   size or 8, whichever is larger.  This constraint MUST be enforced
+   even when using stream ciphers.  Note that the packet length field is
+   also encrypted, and processing it requires special care when sending
+   or receiving packets.
+
+   The minimum size of a packet is 16 (or the cipher block size,
+   whichever is larger) bytes (plus MAC); implementations SHOULD decrypt
+   the length after receiving the first 8 (or cipher block size,
+   whichever is larger) bytes of a packet.
+
+5.1 Maximum Packet Length
+
+   All implementations MUST be able to process packets with uncompressed
+   payload length of 32768 bytes or less and total packet size of 35000
+   bytes or less (including length, padding length, payload, padding,
+   and MAC.). The maximum of 35000 bytes is an arbitrary chosen value
+   larger than uncompressed size. Implementations SHOULD support longer
+   packets, where they might be needed, e.g. if an implementation wants
+   to send a very large number of certificates.  Such packets MAY be
+   sent if the version string indicates that the other party is able to
+   process them. However, implementations SHOULD check that the packet
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 6]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+   length is reasonable for the implementation to avoid
+   denial-of-service and/or buffer overflow attacks.
+
+5.2 Compression
+
+   If compression has been negotiated, the payload field (and only it)
+   will be compressed using the negotiated algorithm. The length field
+   and MAC will be computed from the compressed payload. Encryption will
+   be done after compression.
+
+   Compression MAY be stateful, depending on the method. Compression
+   MUST be independent for each direction, and implementations MUST
+   allow independently choosing the algorithm for each direction.
+
+   The following compression methods are currently defined:
+
+     none     REQUIRED        no compression
+     zlib     OPTIONAL        ZLIB (LZ77) compression
+
+   The "zlib" compression is described in [RFC1950] and in [RFC1951].
+   The compression context is initialized after each key exchange, and
+   is passed from one packet to the next with only a partial flush being
+   performed at the end of each packet. A partial flush means that the
+   current compressed block is ended and all data will be output. If the
+   current block is not a stored block, one or more empty blocks are
+   added after the current block to ensure that there are at least 8
+   bits counting from the start of the end-of-block code of the current
+   block to the end of the packet payload.
+
+   Additional methods may be defined as specified in [SSH-ARCH].
+
+5.3 Encryption
+
+   An encryption algorithm and a key will be negotiated during the key
+   exchange.  When encryption is in effect, the packet length, padding
+   length, payload and padding fields of each packet MUST be encrypted
+   with the given algorithm.
+
+   The encrypted data in all packets sent in one direction SHOULD be
+   considered a single data stream.  For example, initialization vectors
+   SHOULD be passed from the end of one packet to the beginning of the
+   next packet. All ciphers SHOULD use keys with an effective key length
+   of 128 bits or more.
+
+   The ciphers in each direction MUST run independently of each other,
+   and implementations MUST allow independently choosing the algorithm
+   for each direction (if multiple algorithms are allowed by local
+   policy).
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 7]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+   The following ciphers are currently defined:
+
+     3des-cbc         REQUIRED          three-key 3DES in CBC mode
+     blowfish-cbc     OPTIONALi         Blowfish in CBC mode
+     twofish256-cbc   OPTIONAL          Twofish in CBC mode,
+                                        with 256-bit key
+     twofish-cbc      OPTIONAL          alias for "twofish256-cbc" (this
+                                        is being retained for
+                                        historical reasons)
+     twofish192-cbc   OPTIONAL          Twofish with 192-bit key
+     twofish128-cbc   OPTIONAL          Twofish with 128-bit key
+     aes256-cbc       OPTIONAL          AES (Rijndael) in CBC mode,
+                                        with 256-bit key
+     aes192-cbc       OPTIONAL          AES with 192-bit key
+     aes128-cbc       RECOMMENDED       AES with 128-bit key
+     serpent256-cbc   OPTIONAL          Serpent in CBC mode, with
+                                        256-bit key
+     serpent192-cbc   OPTIONAL          Serpent with 192-bit key
+     serpent128-cbc   OPTIONAL          Serpent with 128-bit key
+     arcfour          OPTIONAL          the ARCFOUR stream cipher
+     idea-cbc         OPTIONAL          IDEA in CBC mode
+     cast128-cbc      OPTIONAL          CAST-128 in CBC mode
+     none             OPTIONAL          no encryption; NOT RECOMMENDED
+
+   The "3des-cbc" cipher is three-key triple-DES
+   (encrypt-decrypt-encrypt), where the first 8 bytes of the key are
+   used for the first encryption, the next 8 bytes for the decryption,
+   and the following 8 bytes for the final encryption.  This requires 24
+   bytes of key data (of which 168 bits are actually used).  To
+   implement CBC mode, outer chaining MUST be used (i.e., there is only
+   one initialization vector).  This is a block cipher with 8 byte
+   blocks.  This algorithm is defined in [FIPS-46-3]
+
+   The "blowfish-cbc" cipher is Blowfish in CBC mode, with 128 bit keys
+   [SCHNEIER]. This is a block cipher with 8 byte blocks.
+
+   The "twofish-cbc" or "twofish256-cbc" cipher is Twofish in CBC mode,
+   with 256 bit keys as described [TWOFISH]. This is a block cipher with
+   16 byte blocks.
+
+   The "twofish192-cbc" cipher. Same as above but with 192-bit key.
+
+   The "twofish128-cbc" cipher. Same as above but with 128-bit key.
+
+   The "aes256-cbc" cipher is AES (Advanced Encryption Standard)
+   [FIPS-197], formerly Rijndael, in CBC mode. This version uses 256-bit
+   key.
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 8]
+
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+
+
+   The "aes192-cbc" cipher. Same as above but with 192-bit key.
+
+   The "aes128-cbc" cipher. Same as above but with 128-bit key.
+
+   The "serpent256-cbc" cipher in CBC mode, with 256-bit key as
+   described in the Serpent AES submission.
+
+   The "serpent192-cbc" cipher. Same as above but with 192-bit key.
+
+   The "serpent128-cbc" cipher. Same as above but with 128-bit key.
+
+   The "arcfour" is the Arcfour stream cipher with 128 bit keys. The
+   Arcfour cipher is believed to be compatible with the RC4 cipher
+   [SCHNEIER]. RC4 is a registered trademark of RSA Data Security Inc.
+   Arcfour (and RC4) has problems with weak keys, and should be used
+   with caution.
+
+   The "idea-cbc" cipher is the IDEA cipher in CBC mode [SCHNEIER].
+
+   The "cast128-cbc" cipher is the CAST-128 cipher in CBC mode
+   [RFC2144].
+
+   The "none" algorithm specifies that no encryption is to be done.
+   Note that this method provides no confidentiality protection, and it
+   is not recommended.  Some functionality (e.g. password
+   authentication) may be disabled for security reasons if this cipher
+   is chosen.
+
+   Additional methods may be defined as specified in [SSH-ARCH].
+
+5.4 Data Integrity
+
+   Data integrity is protected by including with each packet a message
+   authentication code (MAC) that is computed from a shared secret,
+   packet sequence number, and the contents of the packet.
+
+   The message authentication algorithm and key are negotiated during
+   key exchange.  Initially, no MAC will be in effect, and its length
+   MUST be zero.  After key exchange, the selected MAC will be computed
+   before encryption from the concatenation of packet data:
+
+     mac = MAC(key, sequence_number || unencrypted_packet)
+
+   where unencrypted_packet is the entire packet without MAC (the length
+   fields, payload and padding), and sequence_number is an implicit
+   packet sequence number represented as uint32.  The sequence number is
+   initialized to zero for the first packet, and is incremented after
+   every packet (regardless of whether encryption or MAC is in use).  It
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004               [Page 9]
+
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+
+
+   is never reset, even if keys/algorithms are renegotiated later.  It
+   wraps around to zero after every 2^32 packets. The packet sequence
+   number itself is not included in the packet sent over the wire.
+
+   The MAC algorithms for each direction MUST run independently, and
+   implementations MUST allow choosing the algorithm independently for
+   both directions.
+
+   The MAC bytes resulting from the MAC algorithm MUST be transmitted
+   without encryption as the last part of the packet.  The number of MAC
+   bytes depends on the algorithm chosen.
+
+   The following MAC algorithms are currently defined:
+
+     hmac-sha1    REQUIRED        HMAC-SHA1 (digest length = key
+                                  length = 20)
+     hmac-sha1-96 RECOMMENDED     first 96 bits of HMAC-SHA1 (digest
+                                  length = 12, key length = 20)
+     hmac-md5     OPTIONAL        HMAC-MD5 (digest length = key
+                                  length = 16)
+     hmac-md5-96  OPTIONAL        first 96 bits of HMAC-MD5 (digest
+                                  length = 12, key length = 16)
+     none         OPTIONAL        no MAC; NOT RECOMMENDED
+
+                                Figure 1
+
+   The "hmac-*" algorithms are described in [RFC2104] The "*-n" MACs use
+   only the first n bits of the resulting value.
+
+   The hash algorithms are described in [SCHNEIER].
+
+   Additional methods may be defined as specified in [SSH-ARCH].
+
+5.5 Key Exchange Methods
+
+   The key exchange method specifies how one-time session keys are
+   generated for encryption and for authentication, and how the server
+   authentication is done.
+
+   Only one REQUIRED key exchange method has been defined:
+
+     diffie-hellman-group1-sha1       REQUIRED
+
+   This method is described later in this document.
+
+   Additional methods may be defined as specified in [SSH-ARCH].
+
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 10]
+
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+
+
+5.6 Public Key Algorithms
+
+   This protocol has been designed to be able to operate with almost any
+   public key format, encoding, and algorithm (signature and/or
+   encryption).
+
+   There are several aspects that define a public key type:
+   o  Key format: how is the key encoded and how are certificates
+      represented.  The key blobs in this protocol MAY contain
+      certificates in addition to keys.
+   o  Signature and/or encryption algorithms.  Some key types may not
+      support both signing and encryption.  Key usage may also be
+      restricted by policy statements in e.g. certificates.  In this
+      case, different key types SHOULD be defined for the different
+      policy alternatives.
+   o  Encoding of signatures and/or encrypted data. This includes but is
+      not limited to padding, byte order, and data formats.
+
+   The following public key and/or certificate formats are currently defined:
+
+   ssh-dss              REQUIRED     sign    Raw DSS Key
+   ssh-rsa              RECOMMENDED  sign    Raw RSA Key
+   x509v3-sign-rsa      OPTIONAL     sign    X.509 certificates (RSA key)
+   x509v3-sign-dss      OPTIONAL     sign    X.509 certificates (DSS key)
+   spki-sign-rsa        OPTIONAL     sign    SPKI certificates (RSA key)
+   spki-sign-dss        OPTIONAL     sign    SPKI certificates (DSS key)
+   pgp-sign-rsa         OPTIONAL     sign    OpenPGP certificates (RSA key)
+   pgp-sign-dss         OPTIONAL     sign    OpenPGP certificates (DSS key)
+
+   Additional key types may be defined as specified in [SSH-ARCH].
+
+   The key type MUST always be explicitly known (from algorithm
+   negotiation or some other source).  It is not normally included in
+   the key blob.
+
+   Certificates and public keys are encoded as follows:
+
+     string   certificate or public key format identifier
+     byte[n]  key/certificate data
+
+   The certificate part may have be a zero length string, but a public
+   key is required. This is the public key that will be used for
+   authentication; the certificate sequence contained in the certificate
+   blob can be used to provide authorization.
+
+   Public key / certifcate formats that do not explicitly specify a
+   signature format identifier MUST use the public key / certificate
+   format identifier as the signature identifier.
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 11]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+   Signatures are encoded as follows:
+     string    signature format identifier (as specified by the
+               public key / cert format)
+     byte[n]   signature blob in format specific encoding.
+
+
+   The "ssh-dss" key format has the following specific encoding:
+
+     string    "ssh-dss"
+     mpint     p
+     mpint     q
+     mpint     g
+     mpint     y
+
+   Here the p, q, g, and y parameters form the signature key blob.
+
+   Signing and verifying using this key format is done according to the
+   Digital Signature Standard [FIPS-186] using the SHA-1 hash. A
+   description can also be found in [SCHNEIER].
+
+   The resulting signature is encoded as follows:
+
+     string    "ssh-dss"
+     string    dss_signature_blob
+
+   dss_signature_blob is encoded as a string containing r followed by s
+   (which are 160 bits long integers, without lengths or padding,
+   unsigned and in network byte order).
+
+   The "ssh-rsa" key format has the following specific encoding:
+
+     string    "ssh-rsa"
+     mpint     e
+     mpint     n
+
+   Here the e and n parameters form the signature key blob.
+
+   Signing and verifying using this key format is done according to
+   [SCHNEIER] and [PKCS1] using the SHA-1 hash.
+
+   The resulting signature is encoded as follows:
+
+     string    "ssh-rsa"
+     string    rsa_signature_blob
+
+   rsa_signature_blob is encoded as a string containing s (which is an
+   integer, without lengths or padding, unsigned and in network byte
+   order).
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 12]
+
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+
+
+   The "spki-sign-rsa" method indicates that the certificate blob
+   contains a sequence of SPKI certificates. The format of SPKI
+   certificates is described in [RFC2693]. This method indicates that
+   the key (or one of the keys in the certificate) is an RSA-key.
+
+   The "spki-sign-dss". As above, but indicates that the key (or one of
+   the keys in the certificate) is a DSS-key.
+
+   The "pgp-sign-rsa" method indicates the certificates, the public key,
+   and the signature are in OpenPGP compatible binary format
+   ([RFC2440]). This method indicates that the key is an RSA-key.
+
+   The "pgp-sign-dss". As above, but indicates that the key is a
+   DSS-key.
+
+6. Key Exchange
+
+   Key exchange begins by each side sending lists of supported
+   algorithms. Each side has a preferred algorithm in each category, and
+   it is assumed that most implementations at any given time will use
+   the same preferred algorithm.  Each side MAY guess which algorithm
+   the other side is using, and MAY send an initial key exchange packet
+   according to the algorithm if appropriate for the preferred method.
+
+   Guess is considered wrong, if:
+   o  the kex algorithm and/or the host key algorithm is guessed wrong
+      (server and client have different preferred algorithm), or
+   o  if any of the other algorithms cannot be agreed upon (the
+      procedure is defined below in Section Section 6.1).
+
+   Otherwise, the guess is considered to be right and the optimistically
+   sent packet MUST be handled as the first key exchange packet.
+
+   However, if the guess was wrong, and a packet was optimistically sent
+   by one or both parties, such packets MUST be ignored (even if the
+   error in the guess would not affect the contents of the initial
+   packet(s)), and the appropriate side MUST send the correct initial
+   packet.
+
+   Server authentication in the key exchange MAY be implicit.  After a
+   key exchange with implicit server authentication, the client MUST
+   wait for response to its service request message before sending any
+   further data.
+
+6.1 Algorithm Negotiation
+
+   Key exchange begins by each side sending the following packet:
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 13]
+
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+
+
+     byte      SSH_MSG_KEXINIT
+     byte[16]  cookie (random bytes)
+     string    kex_algorithms
+     string    server_host_key_algorithms
+     string    encryption_algorithms_client_to_server
+     string    encryption_algorithms_server_to_client
+     string    mac_algorithms_client_to_server
+     string    mac_algorithms_server_to_client
+     string    compression_algorithms_client_to_server
+     string    compression_algorithms_server_to_client
+     string    languages_client_to_server
+     string    languages_server_to_client
+     boolean   first_kex_packet_follows
+     uint32    0 (reserved for future extension)
+
+   Each of the algorithm strings MUST be a comma-separated list of
+   algorithm names (see ''Algorithm Naming'' in [SSH-ARCH]). Each
+   supported (allowed) algorithm MUST be listed in order of preference.
+
+   The first algorithm in each list MUST be the preferred (guessed)
+   algorithm.  Each string MUST contain at least one algorithm name.
+
+
+      cookie
+         The cookie MUST be a random value generated by the sender.  Its
+         purpose is to make it impossible for either side to fully
+         determine the keys and the session identifier.
+
+      kex_algorithms
+         Key exchange algorithms were defined above.  The first
+         algorithm MUST be the preferred (and guessed) algorithm.  If
+         both sides make the same guess, that algorithm MUST be used.
+         Otherwise, the following algorithm MUST be used to choose a key
+         exchange method: iterate over client's kex algorithms, one at a
+         time.  Choose the first algorithm that satisfies the following
+         conditions:
+         +  the server also supports the algorithm,
+         +  if the algorithm requires an encryption-capable host key,
+            there is an encryption-capable algorithm on the server's
+            server_host_key_algorithms that is also supported by the
+            client, and
+         +  if the algorithm requires a signature-capable host key,
+            there is a signature-capable algorithm on the server's
+            server_host_key_algorithms that is also supported by the
+            client.
+         +  If no algorithm satisfying all these conditions can be
+            found, the connection fails, and both sides MUST disconnect.
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 14]
+
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+
+
+      server_host_key_algorithms
+         List of the algorithms supported for the server host key.  The
+         server lists the algorithms for which it has host keys; the
+         client lists the algorithms that it is willing to accept.
+         (There MAY be multiple host keys for a host, possibly with
+         different algorithms.)
+
+         Some host keys may not support both signatures and encryption
+         (this can be determined from the algorithm), and thus not all
+         host keys are valid for all key exchange methods.
+
+         Algorithm selection depends on whether the chosen key exchange
+         algorithm requires a signature or encryption capable host key.
+         It MUST be possible to determine this from the public key
+         algorithm name.  The first algorithm on the client's list that
+         satisfies the requirements and is also supported by the server
+         MUST be chosen.  If there is no such algorithm, both sides MUST
+         disconnect.
+
+      encryption_algorithms
+         Lists the acceptable symmetric encryption algorithms in order
+         of preference.  The chosen encryption algorithm to each
+         direction MUST be the first algorithm  on the client's list
+         that is also on the server's list. If there is no such
+         algorithm, both sides MUST disconnect.
+
+         Note that "none" must be explicitly listed if it is to be
+         acceptable.  The defined algorithm names are listed in Section
+         Section 5.3.
+
+      mac_algorithms
+         Lists the acceptable MAC algorithms in order of preference.
+         The chosen MAC algorithm MUST be the first algorithm on the
+         client's list that is also on the server's list.  If there is
+         no such algorithm, both sides MUST disconnect.
+
+         Note that "none" must be explicitly listed if it is to be
+         acceptable.  The MAC algorithm names are listed in Section
+         Figure 1.
+
+      compression_algorithms
+         Lists the acceptable compression algorithms in order of
+         preference. The chosen compression algorithm MUST be the first
+         algorithm on the client's list that is also on the server's
+         list.  If there is no such algorithm, both sides MUST
+         disconnect.
+
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 15]
+
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+
+
+         Note that "none" must be explicitly listed if it is to be
+         acceptable.  The compression algorithm names are listed in
+         Section Section 5.2.
+
+      languages
+         This is a comma-separated list of language tags in order of
+         preference [RFC3066]. Both parties MAY ignore this list. If
+         there are no language preferences, this list SHOULD be empty.
+         Language tags SHOULD NOT be present unless they are known to be
+         needed by the sending party.
+
+      first_kex_packet_follows
+         Indicates whether a guessed key exchange packet follows.  If a
+         guessed packet will be sent, this MUST be TRUE.  If no guessed
+         packet will be sent, this MUST be FALSE.
+
+         After receiving the SSH_MSG_KEXINIT packet from the other side,
+         each party will know whether their guess was right.  If the
+         other party's guess was wrong, and this field was TRUE, the
+         next packet MUST be silently ignored, and both sides MUST then
+         act as determined by the negotiated key exchange method.  If
+         the guess was right, key exchange MUST continue using the
+         guessed packet.
+
+   After the KEXINIT packet exchange, the key exchange algorithm is run.
+   It may involve several packet exchanges, as specified by the key
+   exchange method.
+
+6.2 Output from Key Exchange
+
+   The key exchange produces two values: a shared secret K, and an
+   exchange hash H.  Encryption and authentication keys are derived from
+   these. The exchange hash H from the first key exchange is
+   additionally used as the session identifier, which is a unique
+   identifier for this connection.  It is used by authentication methods
+   as a part of the data that is signed as a proof of possession of a
+   private key.  Once computed, the session identifier is not changed,
+   even if keys are later re-exchanged.
+
+
+   Each key exchange method specifies a hash function that is used in
+   the key exchange.  The same hash algorithm MUST be used in key
+   derivation. Here, we'll call it HASH.
+
+
+   Encryption keys MUST be computed as HASH of a known value and K as
+   follows:
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 16]
+
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+
+
+   o  Initial IV client to server: HASH(K || H || "A" || session_id)
+      (Here K is encoded as mpint and "A" as byte and session_id as raw
+      data."A" means the single character A, ASCII 65).
+   o  Initial IV server to client: HASH(K || H || "B" || session_id)
+   o  Encryption key client to server: HASH(K || H || "C" || session_id)
+   o  Encryption key server to client: HASH(K || H || "D" || session_id)
+   o  Integrity key client to server: HASH(K || H || "E" || session_id)
+   o  Integrity key server to client: HASH(K || H || "F" || session_id)
+
+   Key data MUST be taken from the beginning of the hash output. 128
+   bits (16 bytes) MUST be used for algorithms with variable-length
+   keys. The only variable key length algorithm defined in this document
+   is arcfour).  For other algorithms, as many bytes as are needed are
+   taken from the beginning of the hash value. If the key length needed
+   is longer than the output of the HASH, the key is extended by
+   computing HASH of the concatenation of K and H and the entire key so
+   far, and appending the resulting bytes (as many as HASH generates) to
+   the key.  This process is repeated until enough key material is
+   available; the key is taken from the beginning of this value. In
+   other words:
+
+     K1 = HASH(K || H || X || session_id)   (X is e.g. "A")
+     K2 = HASH(K || H || K1)
+     K3 = HASH(K || H || K1 || K2)
+     ...
+     key = K1 || K2 || K3 || ...
+
+   This process will lose entropy if the amount of entropy in K is
+   larger than the internal state size of HASH.
+
+6.3 Taking Keys Into Use
+
+   Key exchange ends by each side sending an SSH_MSG_NEWKEYS message.
+   This message is sent with the old keys and algorithms.  All messages
+   sent after this message MUST use the new keys and algorithms.
+
+
+   When this message is received, the new keys and algorithms MUST be
+   taken into use for receiving.
+
+
+   This message is the only valid message after key exchange, in
+   addition to SSH_MSG_DEBUG, SSH_MSG_DISCONNECT and SSH_MSG_IGNORE
+   messages. The purpose of this message is to ensure that a party is
+   able to respond with a disconnect message that the other party can
+   understand if something goes wrong with the key exchange.
+   Implementations MUST NOT accept any other messages after key exchange
+   before receiving SSH_MSG_NEWKEYS.
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 17]
+
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+
+
+     byte      SSH_MSG_NEWKEYS
+
+
+7. Diffie-Hellman Key Exchange
+
+   The Diffie-Hellman key exchange provides a shared secret that can not
+   be determined by either party alone. The key exchange is combined
+   with a signature with the host key to provide host authentication.
+
+
+   In the following description (C is the client, S is the server; p is
+   a large safe prime, g is a generator for a subgroup of GF(p), and q
+   is the order of the subgroup; V_S is S's version string; V_C is C's
+   version string; K_S is S's public host key; I_C is C's KEXINIT
+   message and I_S S's KEXINIT message which have been exchanged before
+   this part begins):
+
+
+   1.  C generates a random number x (1 < x < q) and computes e = g^x
+       mod p.  C sends "e" to S.
+
+   2.  S generates a random number y (0 < y < q) and computes f = g^y
+       mod p.  S receives "e".  It computes K = e^y mod p, H = hash(V_C
+       || V_S || I_C || I_S || K_S || e || f || K) (these elements are
+       encoded according to their types; see below), and signature s on
+       H with its private host key. S sends "K_S || f || s" to C. The
+       signing operation may involve a second hashing operation.
+
+   3.  C verifies that K_S really is the host key for S (e.g. using
+       certificates or a local database). C is also allowed to accept
+       the key without verification; however, doing so will render the
+       protocol insecure against active attacks (but may be desirable
+       for practical reasons in the short term in many environments).  C
+       then computes K = f^x mod p, H = hash(V_C || V_S || I_C || I_S ||
+       K_S || e || f || K), and verifies the signature s on H.
+
+   Either side MUST NOT send or accept e or f values that are not in the
+   range [1, p-1]. If this condition is violated, the key exchange
+   fails.
+
+
+   This is implemented with the following messages.  The hash algorithm
+   for computing the exchange hash is defined by the method name, and is
+   called HASH.  The public key algorithm for signing is negotiated with
+   the KEXINIT messages.
+
+   First, the client sends the following:
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 18]
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+
+
+     byte      SSH_MSG_KEXDH_INIT
+     mpint     e
+
+
+   The server responds with the following:
+
+     byte      SSH_MSG_KEXDH_REPLY
+     string    server public host key and certificates (K_S)
+     mpint     f
+     string    signature of H
+
+   The hash H is computed as the HASH hash of the concatenation of the
+   following:
+
+     string    V_C, the client's version string (CR and NL excluded)
+     string    V_S, the server's version string (CR and NL excluded)
+     string    I_C, the payload of the client's SSH_MSG_KEXINIT
+     string    I_S, the payload of the server's SSH_MSG_KEXINIT
+     string    K_S, the host key
+     mpint     e, exchange value sent by the client
+     mpint     f, exchange value sent by the server
+     mpint     K, the shared secret
+
+   This value is called the exchange hash, and it is used to
+   authenticate the key exchange. The exchange hash SHOULD be kept
+   secret.
+
+
+   The signature algorithm MUST be applied over H, not the original
+   data.  Most signature algorithms include hashing and additional
+   padding.  For example, "ssh-dss" specifies SHA-1 hashing; in that
+   case, the data is first hashed with HASH to compute H, and H is then
+   hashed with SHA-1 as part of the signing operation.
+
+7.1 diffie-hellman-group1-sha1
+
+   The "diffie-hellman-group1-sha1" method specifies Diffie-Hellman key
+   exchange with SHA-1 as HASH, and Oakley group 14 [RFC3526] (2048-bit
+   MODP Group).  It is included below in hexadecimal and decimal.
+
+   The prime p is equal to 2^1024 - 2^960 - 1 + 2^64 * floor( 2^894 Pi +
+   129093 ). Its hexadecimal value is:
+
+         FFFFFFFF FFFFFFFF C90FDAA2 2168C234 C4C6628B 80DC1CD1
+         29024E08 8A67CC74 020BBEA6 3B139B22 514A0879 8E3404DD
+         EF9519B3 CD3A431B 302B0A6D F25F1437 4FE1356D 6D51C245
+         E485B576 625E7EC6 F44C42E9 A637ED6B 0BFF5CB6 F406B7ED
+         EE386BFB 5A899FA5 AE9F2411 7C4B1FE6 49286651 ECE65381
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 19]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+         FFFFFFFF FFFFFFFF.
+
+   In decimal, this value is:
+
+         179769313486231590770839156793787453197860296048756011706444
+         423684197180216158519368947833795864925541502180565485980503
+         646440548199239100050792877003355816639229553136239076508735
+         759914822574862575007425302077447712589550957937778424442426
+         617334727629299387668709205606050270810842907692932019128194
+         467627007.
+
+   The generator used with this prime is g = 2. The group order q is (p
+   - 1) / 2.
+
+8. Key Re-Exchange
+
+   Key re-exchange is started by sending an SSH_MSG_KEXINIT packet when
+   not already doing a key exchange (as described in Section Section
+   6.1). When this message is received, a party MUST respond with its
+   own SSH_MSG_KEXINIT message except when the received SSH_MSG_KEXINIT
+   already was a reply. Either party MAY initiate the re-exchange, but
+   roles MUST NOT be changed (i.e., the server remains the server, and
+   the client remains the client).
+
+
+   Key re-exchange is performed using whatever encryption was in effect
+   when the exchange was started.  Encryption, compression, and MAC
+   methods are not changed before a new SSH_MSG_NEWKEYS is sent after
+   the key exchange (as in the initial key exchange).  Re-exchange is
+   processed identically to the initial key exchange, except for the
+   session identifier that will remain unchanged. It is permissible to
+   change some or all of the algorithms during the re-exchange.  Host
+   keys can also change.  All keys and initialization vectors are
+   recomputed after the exchange.  Compression and encryption contexts
+   are reset.
+
+
+   It is recommended that the keys are changed after each gigabyte of
+   transmitted data or after each hour of connection time, whichever
+   comes sooner. However, since the re-exchange is a public key
+   operation, it requires a fair amount of processing power and should
+   not be performed too often.
+
+
+   More application data may be sent after the SSH_MSG_NEWKEYS packet
+   has been sent; key exchange does not affect the protocols that lie
+   above the SSH transport layer.
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 20]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+9. Service Request
+
+   After the key exchange, the client requests a service. The service is
+   identified by a name. The format of names and procedures for defining
+   new names are defined in [SSH-ARCH].
+
+
+   Currently, the following names have been reserved:
+
+     ssh-userauth
+     ssh-connection
+
+   Similar local naming policy is applied to the service names, as is
+   applied to the algorithm names; a local service should use the
+   "servicename@domain" syntax.
+
+     byte      SSH_MSG_SERVICE_REQUEST
+     string    service name
+
+   If the server rejects the service request, it SHOULD send an
+   appropriate SSH_MSG_DISCONNECT message and MUST disconnect.
+
+
+   When the service starts, it may have access to the session identifier
+   generated during the key exchange.
+
+
+   If the server supports the service (and permits the client to use
+   it), it MUST respond with the following:
+
+     byte      SSH_MSG_SERVICE_ACCEPT
+     string    service name
+
+   Message numbers used by services should be in the area reserved for
+   them (see Section 6 in [SSH-ARCH]).  The transport level will
+   continue to process its own messages.
+
+
+   Note that after a key exchange with implicit server authentication,
+   the client MUST wait for response to its service request message
+   before sending any further data.
+
+10. Additional Messages
+
+   Either party may send any of the following messages at any time.
+
+
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 21]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+10.1 Disconnection Message
+
+     byte      SSH_MSG_DISCONNECT
+     uint32    reason code
+     string    description [RFC2279]
+     string    language tag [RFC3066]
+
+   This message causes immediate termination of the connection.  All
+   implementations MUST be able to process this message; they SHOULD be
+   able to send this message.
+
+   The sender MUST NOT send or receive any data after this message, and
+   the recipient MUST NOT accept any data after receiving this message.
+   The description field gives a more specific explanation in a
+   human-readable form.  The error code gives the reason in a more
+   machine-readable format (suitable for localization), and can have the
+   following values:
+
+     #define SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT      1
+     #define SSH_DISCONNECT_PROTOCOL_ERROR                   2
+     #define SSH_DISCONNECT_KEY_EXCHANGE_FAILED              3
+     #define SSH_DISCONNECT_RESERVED                         4
+     #define SSH_DISCONNECT_MAC_ERROR                        5
+     #define SSH_DISCONNECT_COMPRESSION_ERROR                6
+     #define SSH_DISCONNECT_SERVICE_NOT_AVAILABLE            7
+     #define SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED   8
+     #define SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE          9
+     #define SSH_DISCONNECT_CONNECTION_LOST                 10
+     #define SSH_DISCONNECT_BY_APPLICATION                  11
+     #define SSH_DISCONNECT_TOO_MANY_CONNECTIONS            12
+     #define SSH_DISCONNECT_AUTH_CANCELLED_BY_USER          13
+     #define SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE  14
+     #define SSH_DISCONNECT_ILLEGAL_USER_NAME               15
+
+   If the description string is displayed, control character filtering
+   discussed in [SSH-ARCH] should be used to avoid attacks by sending
+   terminal control characters.
+
+10.2 Ignored Data Message
+
+     byte      SSH_MSG_IGNORE
+     string    data
+
+   All implementations MUST understand (and ignore) this message at any
+   time (after receiving the protocol version). No implementation is
+   required to send them. This message can be used as an additional
+   protection measure against advanced traffic analysis techniques.
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 22]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+10.3 Debug Message
+
+     byte      SSH_MSG_DEBUG
+     boolean   always_display
+     string    message [RFC2279]
+     string    language tag [RFC3066]
+
+   All implementations MUST understand this message, but they are
+   allowed to ignore it.  This message is used to pass the other side
+   information that may help debugging.  If always_display is TRUE, the
+   message SHOULD be displayed.  Otherwise, it SHOULD NOT be displayed
+   unless debugging information has been explicitly requested by the
+   user.
+
+
+   The message doesn't need to contain a newline. It is, however,
+   allowed to consist of multiple lines separated by CRLF (Carriage
+   Return - Line Feed) pairs.
+
+
+   If the message string is displayed, terminal control character
+   filtering discussed in [SSH-ARCH] should be used to avoid attacks by
+   sending terminal control characters.
+
+10.4 Reserved Messages
+
+   An implementation MUST respond to all unrecognized messages with an
+   SSH_MSG_UNIMPLEMENTED message in the order in which the messages were
+   received.  Such messages MUST be otherwise ignored.  Later protocol
+   versions may define other meanings for these message types.
+
+     byte      SSH_MSG_UNIMPLEMENTED
+     uint32    packet sequence number of rejected message
+
+
+11. Summary of Message Numbers
+
+   The following message numbers have been defined in this protocol:
+
+     #define SSH_MSG_DISCONNECT             1
+     #define SSH_MSG_IGNORE                 2
+     #define SSH_MSG_UNIMPLEMENTED          3
+     #define SSH_MSG_DEBUG                  4
+     #define SSH_MSG_SERVICE_REQUEST        5
+     #define SSH_MSG_SERVICE_ACCEPT         6
+
+     #define SSH_MSG_KEXINIT                20
+     #define SSH_MSG_NEWKEYS                21
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 23]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+     /* Numbers 30-49 used for kex packets.
+        Different kex methods may reuse message numbers in
+        this range. */
+
+     #define SSH_MSG_KEXDH_INIT             30
+     #define SSH_MSG_KEXDH_REPLY            31
+
+
+12. IANA Considerations
+
+   This document is part of a set, the IANA considerations for the SSH
+   protocol as defined in [SSH-ARCH], [SSH-TRANS], [SSH-USERAUTH],
+   [SSH-CONNECT] are detailed in [SSH-NUMBERS].
+
+13. Security Considerations
+
+   This protocol provides a secure encrypted channel over an insecure
+   network.  It performs server host authentication, key exchange,
+   encryption, and integrity protection.  It also derives a unique
+   session id that may be used by higher-level protocols.
+
+   Full security considerations for this protocol are provided in
+   Section 8 of [SSH-ARCH]
+
+14. Intellectual Property
+
+   The IETF takes no position regarding the validity or scope of any
+   intellectual property or other rights that might be claimed to
+   pertain to the implementation or use of the technology described in
+   this document or the extent to which any license under such rights
+   might or might not be available; neither does it represent that it
+   has made any effort to identify any such rights. Information on the
+   IETF's procedures with respect to rights in standards-track and
+   standards-related documentation can be found in BCP-11. Copies of
+   claims of rights made available for publication and any assurances of
+   licenses to be made available, or the result of an attempt made to
+   obtain a general license or permission for the use of such
+   proprietary rights by implementers or users of this specification can
+   be obtained from the IETF Secretariat.
+
+   The IETF has been notified of intellectual property rights claimed in
+   regard to some or all of the specification contained in this
+   document. For more information consult the online list of claimed
+   rights.
+
+15. Additional Information
+
+   The current document editor is: [email protected]. Comments on
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 24]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+   this internet draft should be sent to the IETF SECSH working group,
+   details at: http://ietf.org/html.charters/secsh-charter.html
+
+Normative
+
+   [SSH-ARCH]
+              Ylonen, T., "SSH Protocol Architecture", I-D
+              draft-ietf-architecture-15.txt, Oct 2003.
+
+   [SSH-TRANS]
+              Ylonen, T., "SSH Transport Layer Protocol", I-D
+              draft-ietf-transport-17.txt, Oct 2003.
+
+   [SSH-USERAUTH]
+              Ylonen, T., "SSH Authentication Protocol", I-D
+              draft-ietf-userauth-18.txt, Oct 2003.
+
+   [SSH-CONNECT]
+              Ylonen, T., "SSH Connection Protocol", I-D
+              draft-ietf-connect-18.txt, Oct 2003.
+
+   [SSH-NUMBERS]
+              Lehtinen, S. and D. Moffat, "SSH Protocol Assigned
+              Numbers", I-D draft-ietf-secsh-assignednumbers-05.txt, Oct
+              2003.
+
+   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
+              Requirement Levels", BCP 14, RFC 2119, March 1997.
+
+Informative
+
+   [FIPS-186]
+              Federal Information Processing Standards Publication,
+              "FIPS PUB 186, Digital Signature Standard", May 1994.
+
+   [FIPS-197]
+              NIST, "FIPS PUB 197 Advanced Encryption Standard (AES)",
+              November 2001.
+
+   [FIPS-46-3]
+              U.S. Dept. of Commerce, "FIPS PUB 46-3, Data Encryption
+              Standard (DES)", October 1999.
+
+   [RFC2459]  Housley, R., Ford, W., Polk, T. and D. Solo, "Internet
+              X.509 Public Key Infrastructure Certificate and CRL
+              Profile", RFC 2459, January 1999.
+
+   [RFC1034]  Mockapetris, P., "Domain names - concepts and facilities",
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 25]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+              STD 13, RFC 1034, November 1987.
+
+   [RFC3066]  Alvestrand, H., "Tags for the Identification of
+              Languages", BCP 47, RFC 3066, January 2001.
+
+   [RFC1950]  Deutsch, L. and J-L. Gailly, "ZLIB Compressed Data Format
+              Specification version 3.3", RFC 1950, May 1996.
+
+   [RFC1951]  Deutsch, P., "DEFLATE Compressed Data Format Specification
+              version 1.3", RFC 1951, May 1996.
+
+   [RFC2279]  Yergeau, F., "UTF-8, a transformation format of ISO
+              10646", RFC 2279, January 1998.
+
+   [RFC2104]  Krawczyk, H., Bellare, M. and R. Canetti, "HMAC:
+              Keyed-Hashing for Message Authentication", RFC 2104,
+              February 1997.
+
+   [RFC2144]  Adams, C., "The CAST-128 Encryption Algorithm", RFC 2144,
+              May 1997.
+
+   [RFC2440]  Callas, J., Donnerhacke, L., Finney, H. and R. Thayer,
+              "OpenPGP Message Format", RFC 2440, November 1998.
+
+   [RFC2693]  Ellison, C., Frantz, B., Lampson, B., Rivest, R., Thomas,
+              B. and T. Ylonen, "SPKI Certificate Theory", RFC 2693,
+              September 1999.
+
+   [RFC3526]  Kivinen, T. and M. Kojo, "More Modular Exponential (MODP)
+              Diffie-Hellman groups for Internet Key Exchange (IKE)",
+              RFC 3526, May 2003.
+
+   [SCHNEIER]
+              Schneier, B., "Applied Cryptography Second Edition:
+              protocols algorithms and source in code in C", 1996.
+
+   [TWOFISH]  Schneier, B., "The Twofish Encryptions Algorithm: A
+              128-Bit Block Cipher, 1st Edition", March 1999.
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 26]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+Authors' Addresses
+
+   Tatu Ylonen
+   SSH Communications Security Corp
+   Fredrikinkatu 42
+   HELSINKI  FIN-00100
+   Finland
+
+   EMail: [email protected]
+
+
+   Darren J. Moffat (editor)
+   Sun Microsystems, Inc
+   17 Network Circle
+   Menlo Park  95025
+   USA
+
+   EMail: [email protected]
+
+Appendix A. Contibutors
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 27]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+Intellectual Property Statement
+
+   The IETF takes no position regarding the validity or scope of any
+   intellectual property or other rights that might be claimed to
+   pertain to the implementation or use of the technology described in
+   this document or the extent to which any license under such rights
+   might or might not be available; neither does it represent that it
+   has made any effort to identify any such rights. Information on the
+   IETF's procedures with respect to rights in standards-track and
+   standards-related documentation can be found in BCP-11. Copies of
+   claims of rights made available for publication and any assurances of
+   licenses to be made available, or the result of an attempt made to
+   obtain a general license or permission for the use of such
+   proprietary rights by implementors or users of this specification can
+   be obtained from the IETF Secretariat.
+
+   The IETF invites any interested party to bring to its attention any
+   copyrights, patents or patent applications, or other proprietary
+   rights which may cover technology that may be required to practice
+   this standard. Please address the information to the IETF Executive
+   Director.
+
+   The IETF has been notified of intellectual property rights claimed in
+   regard to some or all of the specification contained in this
+   document. For more information consult the online list of claimed
+   rights.
+
+
+Full Copyright Statement
+
+   Copyright (C) The Internet Society (2003). All Rights Reserved.
+
+   This document and translations of it may be copied and furnished to
+   others, and derivative works that comment on or otherwise explain it
+   or assist in its implementation may be prepared, copied, published
+   and distributed, in whole or in part, without restriction of any
+   kind, provided that the above copyright notice and this paragraph are
+   included on all such copies and derivative works. However, this
+   document itself may not be modified in any way, such as by removing
+   the copyright notice or references to the Internet Society or other
+   Internet organizations, except as needed for the purpose of
+   developing Internet standards in which case the procedures for
+   copyrights defined in the Internet Standards process must be
+   followed, or as required to translate it into languages other than
+   English.
+
+   The limited permissions granted above are perpetual and will not be
+   revoked by the Internet Society or its successors or assignees.
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 28]
+
+Internet-Draft        SSH Transport Layer Protocol              Oct 2003
+
+
+   This document and the information contained herein is provided on an
+   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
+   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
+   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
+   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
+   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+
+
+Acknowledgment
+
+   Funding for the RFC Editor function is currently provided by the
+   Internet Society.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Moffat, Editor    Expires March 31, 2004              [Page 29]
\ No newline at end of file
diff --git a/lib/ssh/doc/standard/draft-ietf-secsh-userauth-18.2.ps b/lib/ssh/doc/standard/draft-ietf-secsh-userauth-18.2.ps
new file mode 100644
index 0000000000..be5799dbce
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+(Network Working Group                                          T. Ylonen) s
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+(Internet-Draft                          SSH Communications Security Corp) s
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+(Expires: March 2, 2003                                    D. Moffat, Ed.) s
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+(                                                   Sun Microsystems, Inc) s
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+(                                                          September 2002) s
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+(                      SSH Authentication Protocol) s
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+(                    draft-ietf-secsh-userauth-18.txt) s
+5 591 M
+(Status of this Memo) s
+5 569 M
+(   This document is an Internet-Draft and is in full conformance with) s
+5 558 M
+(   all provisions of Section 10 of RFC2026.) s
+5 536 M
+(   Internet-Drafts are working documents of the Internet Engineering) s
+5 525 M
+(   Task Force \(IETF\), its areas, and its working groups. Note that other) s
+5 514 M
+(   groups may also distribute working documents as Internet-Drafts.) s
+5 492 M
+(   Internet-Drafts are draft documents valid for a maximum of six months) s
+5 481 M
+(   and may be updated, replaced, or obsoleted by other documents at any) s
+5 470 M
+(   time. It is inappropriate to use Internet-Drafts as reference) s
+5 459 M
+(   material or to cite them other than as "work in progress.") s
+5 437 M
+(   The list of current Internet-Drafts can be accessed at http://) s
+5 426 M
+(   www.ietf.org/ietf/1id-abstracts.txt.) s
+5 404 M
+(   The list of Internet-Draft Shadow Directories can be accessed at) s
+5 393 M
+(   http://www.ietf.org/shadow.html.) s
+5 371 M
+(   This Internet-Draft will expire on March 2, 2003.) s
+5 349 M
+(Copyright Notice) s
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+(   Copyright \(C\) The Internet Society \(2002\). All Rights Reserved.) s
+5 305 M
+(Abstract) s
+5 283 M
+(   SSH is a protocol for secure remote login and other secure network) s
+5 272 M
+(   services over an insecure network. This document describes the SSH) s
+5 261 M
+(   authentication protocol framework and public key, password, and) s
+5 250 M
+(   host-based client authentication methods. Additional authentication) s
+5 239 M
+(   methods are described in separate documents. The SSH authentication) s
+5 228 M
+(   protocol runs on top of the SSH transport layer protocol and provides) s
+5 217 M
+(   a single authenticated tunnel for the SSH connection protocol.) s
+5 129 M
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+(Internet-Draft        SSH Authentication Protocol         September 2002) s
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+(Table of Contents) s
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+(   1.    Contributors . . . . . . . . . . . . . . . . . . . . . . . .  3) s
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+(   2.    Introduction . . . . . . . . . . . . . . . . . . . . . . . .  3) s
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+(   3.1.2 Responses to Authentication Requests . . . . . . . . . . . .  5) s
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+(   3.1.3 The "none" Authentication Request  . . . . . . . . . . . . .  6) s
+5 591 M
+(   3.1.4 Completion of User Authentication  . . . . . . . . . . . . .  6) s
+5 580 M
+(   3.1.5 Banner Message . . . . . . . . . . . . . . . . . . . . . . .  7) s
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+(   3.2   Authentication Protocol Message Numbers  . . . . . . . . . .  7) s
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+(   3.3   Public Key Authentication Method: publickey  . . . . . . . .  8) s
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+(   3.4   Password Authentication Method: password . . . . . . . . . . 10) s
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+(   3.5   Host-Based Authentication: hostbased . . . . . . . . . . . . 11) s
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+(   4.    Security Considerations  . . . . . . . . . . . . . . . . . . 12) s
+5 514 M
+(         Normative  . . . . . . . . . . . . . . . . . . . . . . . . . 13) s
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+(         Informative  . . . . . . . . . . . . . . . . . . . . . . . . 13) s
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+(         Intellectual Property and Copyright Statements . . . . . . . 15) s
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+(Internet-Draft        SSH Authentication Protocol         September 2002) s
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+(1. Contributors) s
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+(   The major original contributors of this document were: Tatu Ylonen,) s
+5 657 M
+(   Tero Kivinen, Timo J. Rinne, Sami Lehtinen \(all of SSH Communications) s
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+(   Security Corp\), and Markku-Juhani O. Saarinen \(University of) s
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+(   Jyvaskyla\)) s
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+(   The document editor is: [email protected].  Comments on this) s
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+(   internet draft should be sent to the IETF SECSH working group,) s
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+(   details at: http://ietf.org/html.charters/secsh-charter.html) s
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+(2. Introduction) s
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+(   The SSH authentication protocol is a general-purpose user) s
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+(   authentication protocol. It is intended to be run over the SSH) s
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+(   transport layer protocol [SSH-TRANS]. This protocol assumes that the) s
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+(   underlying protocols provide integrity and confidentiality) s
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+(   protection.) s
+5 481 M
+(   This document should be read only after reading the SSH architecture) s
+5 470 M
+(   document [SSH-ARCH]. This document freely uses terminology and) s
+5 459 M
+(   notation from the architecture document without reference or further) s
+5 448 M
+(   explanation.) s
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+(   The service name for this protocol is "ssh-userauth".) s
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+(   When this protocol starts, it receives the session identifier from) s
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+(   the lower-level protocol \(this is the exchange hash H from the first) s
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+(   private key. This protocol also needs to know whether the lower-level) s
+5 349 M
+(   protocol provides confidentiality protection.) s
+5 327 M
+(3. Conventions Used in This Document) s
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+(   The keywords "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT",) s
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+(   and "MAY" that appear in this document are to be interpreted as) s
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+(   described in [RFC2119]) s
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+(   The used data types and terminology are specified in the architecture) s
+5 250 M
+(   document [SSH-ARCH]) s
+5 228 M
+(   The architecture document also discusses the algorithm naming) s
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+(   conventions that MUST be used with the SSH protocols.) s
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+(   All authentication requests MUST use the following message format.) s
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+(   the authentication method.) s
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+(     byte      SSH_MSG_USERAUTH_REQUEST) s
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+(     string    user name \(in ISO-10646 UTF-8 encoding [RFC2279]\)) s
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+(     string    service name \(in US-ASCII\)) s
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+(     string    method name \(US-ASCII\)) s
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+(   The service name specifies the service to start after authentication.) s
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+5 492 M
+(   one.) s
+5 470 M
+(3.1.2 Responses to Authentication Requests) s
+5 448 M
+(   If the server rejects the authentication request, it MUST respond) s
+5 437 M
+(   with the following:) s
+5 415 M
+(     byte      SSH_MSG_USERAUTH_FAILURE) s
+5 404 M
+(     string    authentications that can continue) s
+5 393 M
+(     boolean   partial success) s
+5 371 M
+(   "Authentications that can continue" is a comma-separated list of) s
+5 360 M
+(   authentication method names that may productively continue the) s
+5 349 M
+(   authentication dialog.) s
+5 327 M
+(   It is RECOMMENDED that servers only include those methods in the list) s
+5 316 M
+(   that are actually useful.  However, it is not illegal to include) s
+5 305 M
+(   methods that cannot be used to authenticate the user.) s
+5 283 M
+(   Already successfully completed authentications SHOULD NOT be included) s
+5 272 M
+(   in the list, unless they really should be performed again for some) s
+5 261 M
+(   reason.) s
+5 239 M
+(   "Partial success" MUST be TRUE if the authentication request to which) s
+5 228 M
+(   this is a response was successful.  It MUST be FALSE if the request) s
+5 217 M
+(   was not successfully processed.) s
+5 195 M
+(   When the server accepts authentication, it MUST respond with the) s
+5 184 M
+(   following:) s
+5 129 M
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+(     byte      SSH_MSG_USERAUTH_SUCCESS) s
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+(   Note that this is not sent after each step in a multi-method) s
+5 657 M
+(   authentication sequence, but only when the authentication is) s
+5 646 M
+(   complete.) s
+5 624 M
+(   The client MAY send several authentication requests without waiting) s
+5 613 M
+(   for responses from previous requests.  The server MUST process each) s
+5 602 M
+(   request completely and acknowledge any failed requests with a) s
+5 591 M
+(   SSH_MSG_USERAUTH_FAILURE message before processing the next request.) s
+5 569 M
+(   A request that results in further exchange of messages will be) s
+5 558 M
+(   aborted by a second request. It is not possible to send a second) s
+5 547 M
+(   request without waiting for a response from the server, if the first) s
+5 536 M
+(   request will result in further exchange of messages.  No) s
+5 525 M
+(   SSH_MSG_USERAUTH_FAILURE message will be sent for the aborted method.) s
+5 503 M
+(   SSH_MSG_USERAUTH_SUCCESS MUST be sent only once. When) s
+5 492 M
+(   SSH_MSG_USERAUTH_SUCCESS has been sent, any further authentication) s
+5 481 M
+(   requests received after that SHOULD be silently ignored.) s
+5 459 M
+(   Any non-authentication messages sent by the client after the request) s
+5 448 M
+(   that resulted in SSH_MSG_USERAUTH_SUCCESS being sent MUST be passed) s
+5 437 M
+(   to the service being run on top of this protocol.  Such messages can) s
+5 426 M
+(   be identified by their message numbers \(see Section Message Numbers) s
+5 415 M
+(   \(Section 3.2\)\).) s
+5 393 M
+(3.1.3 The "none" Authentication Request) s
+5 371 M
+(   A client may request a list of authentication methods that may) s
+5 360 M
+(   continue by using the "none" authentication method.) s
+5 338 M
+(   If no authentication at all is needed for the user, the server MUST) s
+5 327 M
+(   return SSH_MSG_USERAUTH_SUCCESS.  Otherwise, the server MUST return) s
+5 316 M
+(   SSH_MSG_USERAUTH_FAILURE and MAY return with it a list of) s
+5 305 M
+(   authentication methods that can continue.) s
+5 283 M
+(   This method MUST NOT be listed as supported by the server.) s
+5 261 M
+(3.1.4 Completion of User Authentication) s
+5 239 M
+(   Authentication is complete when the server has responded with) s
+5 228 M
+(   SSH_MSG_USERAUTH_SUCCESS; all authentication related messages) s
+5 217 M
+(   received after sending this message SHOULD be silently ignored.) s
+5 195 M
+(   After sending SSH_MSG_USERAUTH_SUCCESS, the server starts the) s
+5 184 M
+(   requested service.) s
+5 129 M
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+(Internet-Draft        SSH Authentication Protocol         September 2002) s
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+(3.1.5 Banner Message) s
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+(   In some jurisdictions, sending a warning message before) s
+5 657 M
+(   authentication may be relevant for getting legal protection.  Many) s
+5 646 M
+(   UNIX machines, for example, normally display text from `/etc/issue',) s
+5 635 M
+(   or use "tcp wrappers" or similar software to display a banner before) s
+5 624 M
+(   issuing a login prompt.) s
+5 602 M
+(   The SSH server may send a SSH_MSG_USERAUTH_BANNER message at any time) s
+5 591 M
+(   before authentication is successful.  This message contains text to) s
+5 580 M
+(   be displayed to the client user before authentication is attempted.) s
+5 569 M
+(   The format is as follows:) s
+5 547 M
+(     byte      SSH_MSG_USERAUTH_BANNER) s
+5 536 M
+(     string    message \(ISO-10646 UTF-8\)) s
+5 525 M
+(     string    language tag \(as defined in [RFC3066]\)) s
+5 503 M
+(   The client SHOULD by default display the message on the screen.) s
+5 492 M
+(   However, since the message is likely to be sent for every login) s
+5 481 M
+(   attempt, and since some client software will need to open a separate) s
+5 470 M
+(   window for this warning, the client software may allow the user to) s
+5 459 M
+(   explicitly disable the display of banners from the server.  The) s
+5 448 M
+(   message may consist of multiple lines.) s
+5 426 M
+(   If the message string is displayed, control character filtering) s
+5 415 M
+(   discussed in [SSH-ARCH] SHOULD be used to avoid attacks by sending) s
+5 404 M
+(   terminal control characters.) s
+5 382 M
+(3.2 Authentication Protocol Message Numbers) s
+5 360 M
+(   All message numbers used by this authentication protocol are in the) s
+5 349 M
+(   range from 50 to 79, which is part of the range reserved for) s
+5 338 M
+(   protocols running on top of the SSH transport layer protocol.) s
+5 316 M
+(   Message numbers of 80 and higher are reserved for protocols running) s
+5 305 M
+(   after this authentication protocol, so receiving one of them before) s
+5 294 M
+(   authentication is complete is an error, to which the server MUST) s
+5 283 M
+(   respond by disconnecting \(preferably with a proper disconnect message) s
+5 272 M
+(   sent first to ease troubleshooting\).) s
+5 250 M
+(   After successful authentication, such messages are passed to the) s
+5 239 M
+(   higher-level service.) s
+5 217 M
+(   These are the general authentication message codes:) s
+5 195 M
+(     #define SSH_MSG_USERAUTH_REQUEST            50) s
+5 184 M
+(     #define SSH_MSG_USERAUTH_FAILURE            51) s
+5 173 M
+(     #define SSH_MSG_USERAUTH_SUCCESS            52) s
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+(Ylonen & Moffat          Expires March 2, 2003                  [Page 7]) s
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+(Internet-Draft        SSH Authentication Protocol         September 2002) s
+5 690 M
+(     #define SSH_MSG_USERAUTH_BANNER             53) s
+5 668 M
+(   In addition to the above, there is a range of message numbers) s
+5 657 M
+(   \(60..79\) reserved for method-specific messages.  These messages are) s
+5 646 M
+(   only sent by the server \(client sends only SSH_MSG_USERAUTH_REQUEST) s
+5 635 M
+(   messages\). Different authentication methods reuse the same message) s
+5 624 M
+(   numbers.) s
+5 602 M
+(3.3 Public Key Authentication Method: publickey) s
+5 580 M
+(   The only REQUIRED authentication method is public key authentication.) s
+5 569 M
+(   All implementations MUST support this method; however, not all users) s
+5 558 M
+(   need to have public keys, and most local policies are not likely to) s
+5 547 M
+(   require public key authentication for all users in the near future.) s
+5 525 M
+(   With this method, the possession of a private key serves as) s
+5 514 M
+(   authentication.  This method works by sending a signature created) s
+5 503 M
+(   with a private key of the user.  The server MUST check that the key) s
+5 492 M
+(   is a valid authenticator for the user, and MUST check that the) s
+5 481 M
+(   signature is valid.  If both hold, the authentication request MUST be) s
+5 470 M
+(   accepted; otherwise it MUST be rejected.  \(Note that the server MAY) s
+5 459 M
+(   require additional authentications after successful authentication.\)) s
+5 437 M
+(   Private keys are often stored in an encrypted form at the client) s
+5 426 M
+(   host, and the user must supply a passphrase before the signature can) s
+5 415 M
+(   be generated. Even if they are not, the signing operation involves) s
+5 404 M
+(   some expensive computation.  To avoid unnecessary processing and user) s
+5 393 M
+(   interaction, the following message is provided for querying whether) s
+5 382 M
+(   authentication using the key would be acceptable.) s
+5 360 M
+(     byte      SSH_MSG_USERAUTH_REQUEST) s
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+(     string    user name) s
+5 338 M
+(     string    service) s
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+(     string    "publickey") s
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+(     boolean   FALSE) s
+5 305 M
+(     string    public key algorithm name) s
+5 294 M
+(     string    public key blob) s
+5 272 M
+(   Public key algorithms are defined in the transport layer) s
+5 261 M
+(   specification [SSH-TRANS]. The public key blob may contain) s
+5 250 M
+(   certificates.) s
+5 228 M
+(   Any public key algorithm may be offered for use in authentication.) s
+5 217 M
+(   In particular, the list is not constrained by what was negotiated) s
+5 206 M
+(   during key exchange.  If the server does not support some algorithm,) s
+5 195 M
+(   it MUST simply reject the request.) s
+5 173 M
+(   The server MUST respond to this message with either) s
+5 129 M
+(Ylonen & Moffat          Expires March 2, 2003                  [Page 8]) s
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+(Internet-Draft        SSH Authentication Protocol         September 2002) s
+5 690 M
+(   SSH_MSG_USERAUTH_FAILURE or with the following:) s
+5 668 M
+(     byte      SSH_MSG_USERAUTH_PK_OK) s
+5 657 M
+(     string    public key algorithm name from the request) s
+5 646 M
+(     string    public key blob from the request) s
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+(   To perform actual authentication, the client MAY then send a) s
+5 613 M
+(   signature generated using the private key.  The client MAY send the) s
+5 602 M
+(   signature directly without first verifying whether the key is) s
+5 591 M
+(   acceptable. The signature is sent using the following packet:) s
+5 569 M
+(     byte      SSH_MSG_USERAUTH_REQUEST) s
+5 558 M
+(     string    user name) s
+5 547 M
+(     string    service) s
+5 536 M
+(     string    "publickey") s
+5 525 M
+(     boolean   TRUE) s
+5 514 M
+(     string    public key algorithm name) s
+5 503 M
+(     string    public key to be used for authentication) s
+5 492 M
+(     string    signature) s
+5 470 M
+(   Signature is a signature by the corresponding private key over the) s
+5 459 M
+(   following data, in the following order:) s
+5 437 M
+(     string    session identifier) s
+5 426 M
+(     byte      SSH_MSG_USERAUTH_REQUEST) s
+5 415 M
+(     string    user name) s
+5 404 M
+(     string    service) s
+5 393 M
+(     string    "publickey") s
+5 382 M
+(     boolean   TRUE) s
+5 371 M
+(     string    public key algorithm name) s
+5 360 M
+(     string    public key to be used for authentication) s
+5 338 M
+(   When the server receives this message, it MUST check whether the) s
+5 327 M
+(   supplied key is acceptable for authentication, and if so, it MUST) s
+5 316 M
+(   check whether the signature is correct.) s
+5 294 M
+(   If both checks succeed, this method is successful.  Note that the) s
+5 283 M
+(   server may require additional authentications.  The server MUST) s
+5 272 M
+(   respond with SSH_MSG_USERAUTH_SUCCESS \(if no more authentications are) s
+5 261 M
+(   needed\), or SSH_MSG_USERAUTH_FAILURE \(if the request failed, or more) s
+5 250 M
+(   authentications are needed\).) s
+5 228 M
+(   The following method-specific message numbers are used by the) s
+5 217 M
+(   publickey authentication method.) s
+5 195 M
+(     /* Key-based */) s
+5 184 M
+(     #define SSH_MSG_USERAUTH_PK_OK              60) s
+5 129 M
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+(Internet-Draft        SSH Authentication Protocol         September 2002) s
+5 690 M
+(3.4 Password Authentication Method: password) s
+5 668 M
+(   Password authentication uses the following packets.  Note that a) s
+5 657 M
+(   server MAY request the user to change the password.  All) s
+5 646 M
+(   implementations SHOULD support password authentication.) s
+5 624 M
+(     byte      SSH_MSG_USERAUTH_REQUEST) s
+5 613 M
+(     string    user name) s
+5 602 M
+(     string    service) s
+5 591 M
+(     string    "password") s
+5 580 M
+(     boolean   FALSE) s
+5 569 M
+(     string    plaintext password \(ISO-10646 UTF-8\)) s
+5 547 M
+(   Note that the password is encoded in ISO-10646 UTF-8.  It is up to) s
+5 536 M
+(   the server how it interprets the password and validates it against) s
+5 525 M
+(   the password database.  However, if the client reads the password in) s
+5 514 M
+(   some other encoding \(e.g., ISO 8859-1 \(ISO Latin1\)\), it MUST convert) s
+5 503 M
+(   the password to ISO-10646 UTF-8 before transmitting, and the server) s
+5 492 M
+(   MUST convert the password to the encoding used on that system for) s
+5 481 M
+(   passwords.) s
+5 459 M
+(   Note that even though the cleartext password is transmitted in the) s
+5 448 M
+(   packet, the entire packet is encrypted by the transport layer.  Both) s
+5 437 M
+(   the server and the client should check whether the underlying) s
+5 426 M
+(   transport layer provides confidentiality \(i.e., if encryption is) s
+5 415 M
+(   being used\).  If no confidentiality is provided \(none cipher\),) s
+5 404 M
+(   password authentication SHOULD be disabled.  If there is no) s
+5 393 M
+(   confidentiality or no MAC, password change SHOULD be disabled.) s
+5 371 M
+(   Normally, the server responds to this message with success or) s
+5 360 M
+(   failure. However, if the password has expired the server SHOULD) s
+5 349 M
+(   indicate this by responding with SSH_MSG_USERAUTH_PASSWD_CHANGEREQ.) s
+5 338 M
+(   In anycase the server MUST NOT allow an expired password to be used) s
+5 327 M
+(   for authentication.) s
+5 305 M
+(     byte      SSH_MSG_USERAUTH_PASSWD_CHANGEREQ) s
+5 294 M
+(     string    prompt \(ISO-10646 UTF-8\)) s
+5 283 M
+(     string    language tag \(as defined in [RFC3066]\)) s
+5 261 M
+(   In this case, the client MAY continue with a different authentication) s
+5 250 M
+(   method, or request a new password from the user and retry password) s
+5 239 M
+(   authentication using the following message. The client MAY also send) s
+5 228 M
+(   this message instead of the normal password authentication request) s
+5 217 M
+(   without the server asking for it.) s
+5 195 M
+(     byte      SSH_MSG_USERAUTH_REQUEST) s
+5 184 M
+(     string    user name) s
+5 173 M
+(     string    service) s
+5 129 M
+(Ylonen & Moffat          Expires March 2, 2003                 [Page 10]) s
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+(Internet-Draft        SSH Authentication Protocol         September 2002) s
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+(     string    "password") s
+5 679 M
+(     boolean   TRUE) s
+5 668 M
+(     string    plaintext old password \(ISO-10646 UTF-8\)) s
+5 657 M
+(     string    plaintext new password \(ISO-10646 UTF-8\)) s
+5 635 M
+(   The server must reply to request message with) s
+5 624 M
+(   SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE, or another) s
+5 613 M
+(   SSH_MSG_USERAUTH_PASSWD_CHANGEREQ.  The meaning of these is as) s
+5 602 M
+(   follows:) s
+5 580 M
+(      SSH_MSG_USERAUTH_SUCCESS The password has been changed, and) s
+5 569 M
+(      authentication has been successfully completed.) s
+5 547 M
+(      SSH_MSG_USERAUTH_FAILURE with partial success The password has) s
+5 536 M
+(      been changed, but more authentications are needed.) s
+5 514 M
+(      SSH_MSG_USERAUTH_FAILURE without partial success The password has) s
+5 503 M
+(      not been changed.  Either password changing was not supported, or) s
+5 492 M
+(      the old password was bad.  Note that if the server has already) s
+5 481 M
+(      sent SSH_MSG_USERAUTH_PASSWD_CHANGEREQ, we know that it supports) s
+5 470 M
+(      changing the password.) s
+5 448 M
+(      SSH_MSG_USERAUTH_CHANGEREQ The password was not changed because) s
+5 437 M
+(      the new password was not acceptable \(e.g. too easy to guess\).) s
+5 415 M
+(   The following method-specific message numbers are used by the) s
+5 404 M
+(   password authentication method.) s
+5 382 M
+(     #define SSH_MSG_USERAUTH_PASSWD_CHANGEREQ   60) s
+5 349 M
+(3.5 Host-Based Authentication: hostbased) s
+5 327 M
+(   Some sites wish to allow authentication based on the host where the) s
+5 316 M
+(   user is coming from, and the user name on the remote host.  While) s
+5 305 M
+(   this form of authentication is not suitable for high-security sites,) s
+5 294 M
+(   it can be very convenient in many environments.  This form of) s
+5 283 M
+(   authentication is OPTIONAL. When used, special care SHOULD be taken) s
+5 272 M
+(   to prevent a regular user from obtaining the private host key.) s
+5 250 M
+(   The client requests this form of authentication by sending the) s
+5 239 M
+(   following message.  It is similar to the UNIX "rhosts" and) s
+5 228 M
+(   "hosts.equiv" styles of authentication, except that the identity of) s
+5 217 M
+(   the client host is checked more rigorously.) s
+5 195 M
+(   This method works by having the client send a signature created with) s
+5 184 M
+(   the private key of the client host, which the server checks with that) s
+5 173 M
+(   host's public key.  Once the client host's identity is established,) s
+5 129 M
+(Ylonen & Moffat          Expires March 2, 2003                 [Page 11]) s
+_R
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+(Internet-Draft        SSH Authentication Protocol         September 2002) s
+5 690 M
+(   authorization \(but no further authentication\) is performed based on) s
+5 679 M
+(   the user names on the server and the client, and the client host) s
+5 668 M
+(   name.) s
+5 646 M
+(     byte      SSH_MSG_USERAUTH_REQUEST) s
+5 635 M
+(     string    user name) s
+5 624 M
+(     string    service) s
+5 613 M
+(     string    "hostbased") s
+5 602 M
+(     string    public key algorithm for host key) s
+5 591 M
+(     string    public host key and certificates for client host) s
+5 580 M
+(     string    client host name \(FQDN; US-ASCII\)) s
+5 569 M
+(     string    user name on the client host \(ISO-10646 UTF-8\)) s
+5 558 M
+(     string    signature) s
+5 536 M
+(   Public key algorithm names for use in "public key algorithm for host) s
+5 525 M
+(   key" are defined in the transport layer specification.  The "public) s
+5 514 M
+(   host key for client host" may include certificates.) s
+5 492 M
+(   Signature is a signature with the private host key of the following) s
+5 481 M
+(   data, in this order:) s
+5 459 M
+(     string    session identifier) s
+5 448 M
+(     byte      SSH_MSG_USERAUTH_REQUEST) s
+5 437 M
+(     string    user name) s
+5 426 M
+(     string    service) s
+5 415 M
+(     string    "hostbased") s
+5 404 M
+(     string    public key algorithm for host key) s
+5 393 M
+(     string    public host key and certificates for client host) s
+5 382 M
+(     string    client host name \(FQDN; US-ASCII\)) s
+5 371 M
+(     string    user name on the client host\(ISO-10646 UTF-8\)) s
+5 349 M
+(   The server MUST verify that the host key actually belongs to the) s
+5 338 M
+(   client host named in the message, that the given user on that host is) s
+5 327 M
+(   allowed to log in, and that the signature is a valid signature on the) s
+5 316 M
+(   appropriate value by the given host key.  The server MAY ignore the) s
+5 305 M
+(   client user name, if it wants to authenticate only the client host.) s
+5 283 M
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+5 272 M
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+(   this may require special handling for connections coming through a) s
+5 228 M
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+5 206 M
+(4. Security Considerations) s
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+5 646 M
+(   methods that rely on secret data.) s
+5 624 M
+(   Full security considerations for this protocol are provided in) s
+5 613 M
+(   Section 8 of [SSH-ARCH]) s
+5 591 M
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+5 569 M
+(   [SSH-ARCH]) s
+5 558 M
+(              Ylonen, T., "SSH Protocol Architecture", I-D) s
+5 547 M
+(              draft-ietf-architecture-15.txt, Oct 2003.) s
+5 525 M
+(   [SSH-TRANS]) s
+5 514 M
+(              Ylonen, T., "SSH Transport Layer Protocol", I-D) s
+5 503 M
+(              draft-ietf-transport-17.txt, Oct 2003.) s
+5 481 M
+(   [SSH-USERAUTH]) s
+5 470 M
+(              Ylonen, T., "SSH Authentication Protocol", I-D) s
+5 459 M
+(              draft-ietf-userauth-18.txt, Oct 2003.) s
+5 437 M
+(   [SSH-CONNECT]) s
+5 426 M
+(              Ylonen, T., "SSH Connection Protocol", I-D) s
+5 415 M
+(              draft-ietf-connect-18.txt, Oct 2003.) s
+5 393 M
+(   [SSH-NUMBERS]) s
+5 382 M
+(              Lehtinen, S. and D. Moffat, "SSH Protocol Assigned) s
+5 371 M
+(              Numbers", I-D draft-ietf-secsh-assignednumbers-05.txt, Oct) s
+5 360 M
+(              2003.) s
+5 338 M
+(   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate) s
+5 327 M
+(              Requirement Levels", BCP 14, RFC 2119, March 1997.) s
+5 305 M
+(Informative) s
+5 283 M
+(   [RFC3066]  Alvestrand, H., "Tags for the Identification of) s
+5 272 M
+(              Languages", BCP 47, RFC 3066, January 2001.) s
+5 250 M
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+5 239 M
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+5 690 M
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+5 657 M
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+5 646 M
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+5 525 M
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+(Internet-Draft        SSH Authentication Protocol         September 2002) s
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+5 668 M
+(   The IETF takes no position regarding the validity or scope of any) s
+5 657 M
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+5 646 M
+(   pertain to the implementation or use of the technology described in) s
+5 635 M
+(   this document or the extent to which any license under such rights) s
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+(   might or might not be available; neither does it represent that it) s
+5 613 M
+(   has made any effort to identify any such rights. Information on the) s
+5 602 M
+(   IETF's procedures with respect to rights in standards-track and) s
+5 591 M
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+5 580 M
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+5 569 M
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+5 558 M
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+5 547 M
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+5 514 M
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+5 492 M
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+5 470 M
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+5 448 M
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+(   regard to some or all of the specification contained in this) s
+5 426 M
+(   document. For more information consult the online list of claimed) s
+5 415 M
+(   rights.) s
+5 382 M
+(Full Copyright Statement) s
+5 360 M
+(   Copyright \(C\) The Internet Society \(2002\). All Rights Reserved.) s
+5 338 M
+(   This document and translations of it may be copied and furnished to) s
+5 327 M
+(   others, and derivative works that comment on or otherwise explain it) s
+5 316 M
+(   or assist in its implementation may be prepared, copied, published) s
+5 305 M
+(   and distributed, in whole or in part, without restriction of any) s
+5 294 M
+(   kind, provided that the above copyright notice and this paragraph are) s
+5 283 M
+(   included on all such copies and derivative works. However, this) s
+5 272 M
+(   document itself may not be modified in any way, such as by removing) s
+5 261 M
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+5 250 M
+(   Internet organizations, except as needed for the purpose of) s
+5 239 M
+(   developing Internet standards in which case the procedures for) s
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+(   copyrights defined in the Internet Standards process must be) s
+5 217 M
+(   followed, or as required to translate it into languages other than) s
+5 206 M
+(   English.) s
+5 184 M
+(   The limited permissions granted above are perpetual and will not be) s
+5 173 M
+(   revoked by the Internet Society or its successors or assignees.) s
+5 129 M
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+(   This document and the information contained herein is provided on an) s
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+(   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING) s
+5 668 M
+(   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING) s
+5 657 M
+(   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION) s
+5 646 M
+(   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF) s
+5 635 M
+(   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.) s
+5 602 M
+(Acknowledgment) s
+5 580 M
+(   Funding for the RFC Editor function is currently provided by the) s
+5 569 M
+(   Internet Society.) s
+5 129 M
+(Ylonen & Moffat          Expires March 2, 2003                 [Page 16]) s
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+PStoPSsaved restore
+%%Trailer
+%%Pages: 16
+%%DocumentNeededResources: font Courier-Bold Courier 
+%%EOF
diff --git a/lib/ssh/doc/standard/draft-ietf-secsh-userauth-18.txt b/lib/ssh/doc/standard/draft-ietf-secsh-userauth-18.txt
new file mode 100644
index 0000000000..9dae578a35
--- /dev/null
+++ b/lib/ssh/doc/standard/draft-ietf-secsh-userauth-18.txt
@@ -0,0 +1,896 @@
+
+
+
+Network Working Group                                          T. Ylonen
+Internet-Draft                          SSH Communications Security Corp
+Expires: March 2, 2003                                    D. Moffat, Ed.
+                                                   Sun Microsystems, Inc
+                                                          September 2002
+
+
+                      SSH Authentication Protocol
+                    draft-ietf-secsh-userauth-18.txt
+
+Status of this Memo
+
+   This document is an Internet-Draft and is in full conformance with
+   all provisions of Section 10 of RFC2026.
+
+   Internet-Drafts are working documents of the Internet Engineering
+   Task Force (IETF), its areas, and its working groups. Note that other
+   groups may also distribute working documents as Internet-Drafts.
+
+   Internet-Drafts are draft documents valid for a maximum of six months
+   and may be updated, replaced, or obsoleted by other documents at any
+   time. It is inappropriate to use Internet-Drafts as reference
+   material or to cite them other than as "work in progress."
+
+   The list of current Internet-Drafts can be accessed at http://
+   www.ietf.org/ietf/1id-abstracts.txt.
+
+   The list of Internet-Draft Shadow Directories can be accessed at
+   http://www.ietf.org/shadow.html.
+
+   This Internet-Draft will expire on March 2, 2003.
+
+Copyright Notice
+
+   Copyright (C) The Internet Society (2002). All Rights Reserved.
+
+Abstract
+
+   SSH is a protocol for secure remote login and other secure network
+   services over an insecure network. This document describes the SSH
+   authentication protocol framework and public key, password, and
+   host-based client authentication methods. Additional authentication
+   methods are described in separate documents. The SSH authentication
+   protocol runs on top of the SSH transport layer protocol and provides
+   a single authenticated tunnel for the SSH connection protocol.
+
+
+
+
+
+
+
+Ylonen & Moffat          Expires March 2, 2003                  [Page 1]
+
+Internet-Draft        SSH Authentication Protocol         September 2002
+
+
+Table of Contents
+
+   1.    Contributors . . . . . . . . . . . . . . . . . . . . . . . .  3
+   2.    Introduction . . . . . . . . . . . . . . . . . . . . . . . .  3
+   3.    Conventions Used in This Document  . . . . . . . . . . . . .  3
+   3.1   The Authentication Protocol Framework  . . . . . . . . . . .  3
+   3.1.1 Authentication Requests  . . . . . . . . . . . . . . . . . .  4
+   3.1.2 Responses to Authentication Requests . . . . . . . . . . . .  5
+   3.1.3 The "none" Authentication Request  . . . . . . . . . . . . .  6
+   3.1.4 Completion of User Authentication  . . . . . . . . . . . . .  6
+   3.1.5 Banner Message . . . . . . . . . . . . . . . . . . . . . . .  7
+   3.2   Authentication Protocol Message Numbers  . . . . . . . . . .  7
+   3.3   Public Key Authentication Method: publickey  . . . . . . . .  8
+   3.4   Password Authentication Method: password . . . . . . . . . . 10
+   3.5   Host-Based Authentication: hostbased . . . . . . . . . . . . 11
+   4.    Security Considerations  . . . . . . . . . . . . . . . . . . 12
+         Normative  . . . . . . . . . . . . . . . . . . . . . . . . . 13
+         Informative  . . . . . . . . . . . . . . . . . . . . . . . . 13
+         Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 14
+         Intellectual Property and Copyright Statements . . . . . . . 15
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Ylonen & Moffat          Expires March 2, 2003                  [Page 2]
+
+Internet-Draft        SSH Authentication Protocol         September 2002
+
+
+1. Contributors
+
+   The major original contributors of this document were: Tatu Ylonen,
+   Tero Kivinen, Timo J. Rinne, Sami Lehtinen (all of SSH Communications
+   Security Corp), and Markku-Juhani O. Saarinen (University of
+   Jyvaskyla)
+
+   The document editor is: [email protected].  Comments on this
+   internet draft should be sent to the IETF SECSH working group,
+   details at: http://ietf.org/html.charters/secsh-charter.html
+
+2. Introduction
+
+   The SSH authentication protocol is a general-purpose user
+   authentication protocol. It is intended to be run over the SSH
+   transport layer protocol [SSH-TRANS]. This protocol assumes that the
+   underlying protocols provide integrity and confidentiality
+   protection.
+
+   This document should be read only after reading the SSH architecture
+   document [SSH-ARCH]. This document freely uses terminology and
+   notation from the architecture document without reference or further
+   explanation.
+
+   The service name for this protocol is "ssh-userauth".
+
+   When this protocol starts, it receives the session identifier from
+   the lower-level protocol (this is the exchange hash H from the first
+   key exchange). The session identifier uniquely identifies this
+   session and is suitable for signing in order to prove ownership of a
+   private key. This protocol also needs to know whether the lower-level
+   protocol provides confidentiality protection.
+
+3. Conventions Used in This Document
+
+   The keywords "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT",
+   and "MAY" that appear in this document are to be interpreted as
+   described in [RFC2119]
+
+   The used data types and terminology are specified in the architecture
+   document [SSH-ARCH]
+
+   The architecture document also discusses the algorithm naming
+   conventions that MUST be used with the SSH protocols.
+
+3.1 The Authentication Protocol Framework
+
+   The server drives the authentication by telling the client which
+
+
+
+Ylonen & Moffat          Expires March 2, 2003                  [Page 3]
+
+Internet-Draft        SSH Authentication Protocol         September 2002
+
+
+   authentication methods can be used to continue the exchange at any
+   given time. The client has the freedom to try the methods listed by
+   the server in any order. This gives the server complete control over
+   the authentication process if desired, but also gives enough
+   flexibility for the client to use the methods it supports or that are
+   most convenient for the user, when multiple methods are offered by
+   the server.
+
+   Authentication methods are identified by their name, as defined in
+   [SSH-ARCH].  The "none" method is reserved, and MUST NOT be listed as
+   supported.  However, it MAY be sent by the client.  The server MUST
+   always reject this request, unless the client is to be allowed in
+   without any authentication, in which case the server MUST accept this
+   request.  The main purpose of sending this request is to get the list
+   of supported methods from the server.
+
+   The server SHOULD have a timeout for authentication, and disconnect
+   if the authentication has not been accepted within the timeout
+   period. The RECOMMENDED timeout period is 10 minutes.  Additionally,
+   the implementation SHOULD limit the number of failed authentication
+   attempts a client may perform in a single session (the RECOMMENDED
+   limit is 20 attempts).  If the threshold is exceeded, the server
+   SHOULD disconnect.
+
+3.1.1 Authentication Requests
+
+   All authentication requests MUST use the following message format.
+   Only the first few fields are defined; the remaining fields depend on
+   the authentication method.
+
+     byte      SSH_MSG_USERAUTH_REQUEST
+     string    user name (in ISO-10646 UTF-8 encoding [RFC2279])
+     string    service name (in US-ASCII)
+     string    method name (US-ASCII)
+     The rest of the packet is method-specific.
+
+   The user name and service are repeated in every new authentication
+   attempt, and MAY change.  The server implementation MUST carefully
+   check them in every message, and MUST flush any accumulated
+   authentication states if they change.  If it is unable to flush some
+   authentication state, it MUST disconnect if the user or service name
+   changes.
+
+   The service name specifies the service to start after authentication.
+   There may be several different authenticated services provided.  If
+   the requested service is not available, the server MAY disconnect
+   immediately or at any later time.  Sending a proper disconnect
+   message is RECOMMENDED.  In any case, if the service does not exist,
+
+
+
+Ylonen & Moffat          Expires March 2, 2003                  [Page 4]
+
+Internet-Draft        SSH Authentication Protocol         September 2002
+
+
+   authentication MUST NOT be accepted.
+
+   If the requested user does not exist, the server MAY disconnect, or
+   MAY send a bogus list of acceptable authentication methods, but never
+   accept any.  This makes it possible for the server to avoid
+   disclosing information on which accounts exist.  In any case, if the
+   user does not exist, the authentication request MUST NOT be accepted.
+
+   While there is usually little point for clients to send requests that
+   the server does not list as acceptable, sending such requests is not
+   an error, and the server SHOULD simply reject requests that it does
+   not recognize.
+
+   An authentication request MAY result in a further exchange of
+   messages.  All such messages depend on the authentication method
+   used, and the client MAY at any time continue with a new
+   SSH_MSG_USERAUTH_REQUEST message, in which case the server MUST
+   abandon the previous authentication attempt and continue with the new
+   one.
+
+3.1.2 Responses to Authentication Requests
+
+   If the server rejects the authentication request, it MUST respond
+   with the following:
+
+     byte      SSH_MSG_USERAUTH_FAILURE
+     string    authentications that can continue
+     boolean   partial success
+
+   "Authentications that can continue" is a comma-separated list of
+   authentication method names that may productively continue the
+   authentication dialog.
+
+   It is RECOMMENDED that servers only include those methods in the list
+   that are actually useful.  However, it is not illegal to include
+   methods that cannot be used to authenticate the user.
+
+   Already successfully completed authentications SHOULD NOT be included
+   in the list, unless they really should be performed again for some
+   reason.
+
+   "Partial success" MUST be TRUE if the authentication request to which
+   this is a response was successful.  It MUST be FALSE if the request
+   was not successfully processed.
+
+   When the server accepts authentication, it MUST respond with the
+   following:
+
+
+
+
+Ylonen & Moffat          Expires March 2, 2003                  [Page 5]
+
+Internet-Draft        SSH Authentication Protocol         September 2002
+
+
+     byte      SSH_MSG_USERAUTH_SUCCESS
+
+   Note that this is not sent after each step in a multi-method
+   authentication sequence, but only when the authentication is
+   complete.
+
+   The client MAY send several authentication requests without waiting
+   for responses from previous requests.  The server MUST process each
+   request completely and acknowledge any failed requests with a
+   SSH_MSG_USERAUTH_FAILURE message before processing the next request.
+
+   A request that results in further exchange of messages will be
+   aborted by a second request. It is not possible to send a second
+   request without waiting for a response from the server, if the first
+   request will result in further exchange of messages.  No
+   SSH_MSG_USERAUTH_FAILURE message will be sent for the aborted method.
+
+   SSH_MSG_USERAUTH_SUCCESS MUST be sent only once. When
+   SSH_MSG_USERAUTH_SUCCESS has been sent, any further authentication
+   requests received after that SHOULD be silently ignored.
+
+   Any non-authentication messages sent by the client after the request
+   that resulted in SSH_MSG_USERAUTH_SUCCESS being sent MUST be passed
+   to the service being run on top of this protocol.  Such messages can
+   be identified by their message numbers (see Section Message Numbers
+   (Section 3.2)).
+
+3.1.3 The "none" Authentication Request
+
+   A client may request a list of authentication methods that may
+   continue by using the "none" authentication method.
+
+   If no authentication at all is needed for the user, the server MUST
+   return SSH_MSG_USERAUTH_SUCCESS.  Otherwise, the server MUST return
+   SSH_MSG_USERAUTH_FAILURE and MAY return with it a list of
+   authentication methods that can continue.
+
+   This method MUST NOT be listed as supported by the server.
+
+3.1.4 Completion of User Authentication
+
+   Authentication is complete when the server has responded with
+   SSH_MSG_USERAUTH_SUCCESS; all authentication related messages
+   received after sending this message SHOULD be silently ignored.
+
+   After sending SSH_MSG_USERAUTH_SUCCESS, the server starts the
+   requested service.
+
+
+
+
+Ylonen & Moffat          Expires March 2, 2003                  [Page 6]
+
+Internet-Draft        SSH Authentication Protocol         September 2002
+
+
+3.1.5 Banner Message
+
+   In some jurisdictions, sending a warning message before
+   authentication may be relevant for getting legal protection.  Many
+   UNIX machines, for example, normally display text from `/etc/issue',
+   or use "tcp wrappers" or similar software to display a banner before
+   issuing a login prompt.
+
+   The SSH server may send a SSH_MSG_USERAUTH_BANNER message at any time
+   before authentication is successful.  This message contains text to
+   be displayed to the client user before authentication is attempted.
+   The format is as follows:
+
+     byte      SSH_MSG_USERAUTH_BANNER
+     string    message (ISO-10646 UTF-8)
+     string    language tag (as defined in [RFC3066])
+
+   The client SHOULD by default display the message on the screen.
+   However, since the message is likely to be sent for every login
+   attempt, and since some client software will need to open a separate
+   window for this warning, the client software may allow the user to
+   explicitly disable the display of banners from the server.  The
+   message may consist of multiple lines.
+
+   If the message string is displayed, control character filtering
+   discussed in [SSH-ARCH] SHOULD be used to avoid attacks by sending
+   terminal control characters.
+
+3.2 Authentication Protocol Message Numbers
+
+   All message numbers used by this authentication protocol are in the
+   range from 50 to 79, which is part of the range reserved for
+   protocols running on top of the SSH transport layer protocol.
+
+   Message numbers of 80 and higher are reserved for protocols running
+   after this authentication protocol, so receiving one of them before
+   authentication is complete is an error, to which the server MUST
+   respond by disconnecting (preferably with a proper disconnect message
+   sent first to ease troubleshooting).
+
+   After successful authentication, such messages are passed to the
+   higher-level service.
+
+   These are the general authentication message codes:
+
+     #define SSH_MSG_USERAUTH_REQUEST            50
+     #define SSH_MSG_USERAUTH_FAILURE            51
+     #define SSH_MSG_USERAUTH_SUCCESS            52
+
+
+
+Ylonen & Moffat          Expires March 2, 2003                  [Page 7]
+
+Internet-Draft        SSH Authentication Protocol         September 2002
+
+
+     #define SSH_MSG_USERAUTH_BANNER             53
+
+   In addition to the above, there is a range of message numbers
+   (60..79) reserved for method-specific messages.  These messages are
+   only sent by the server (client sends only SSH_MSG_USERAUTH_REQUEST
+   messages). Different authentication methods reuse the same message
+   numbers.
+
+3.3 Public Key Authentication Method: publickey
+
+   The only REQUIRED authentication method is public key authentication.
+   All implementations MUST support this method; however, not all users
+   need to have public keys, and most local policies are not likely to
+   require public key authentication for all users in the near future.
+
+   With this method, the possession of a private key serves as
+   authentication.  This method works by sending a signature created
+   with a private key of the user.  The server MUST check that the key
+   is a valid authenticator for the user, and MUST check that the
+   signature is valid.  If both hold, the authentication request MUST be
+   accepted; otherwise it MUST be rejected.  (Note that the server MAY
+   require additional authentications after successful authentication.)
+
+   Private keys are often stored in an encrypted form at the client
+   host, and the user must supply a passphrase before the signature can
+   be generated. Even if they are not, the signing operation involves
+   some expensive computation.  To avoid unnecessary processing and user
+   interaction, the following message is provided for querying whether
+   authentication using the key would be acceptable.
+
+     byte      SSH_MSG_USERAUTH_REQUEST
+     string    user name
+     string    service
+     string    "publickey"
+     boolean   FALSE
+     string    public key algorithm name
+     string    public key blob
+
+   Public key algorithms are defined in the transport layer
+   specification [SSH-TRANS]. The public key blob may contain
+   certificates.
+
+   Any public key algorithm may be offered for use in authentication.
+   In particular, the list is not constrained by what was negotiated
+   during key exchange.  If the server does not support some algorithm,
+   it MUST simply reject the request.
+
+   The server MUST respond to this message with either
+
+
+
+Ylonen & Moffat          Expires March 2, 2003                  [Page 8]
+
+Internet-Draft        SSH Authentication Protocol         September 2002
+
+
+   SSH_MSG_USERAUTH_FAILURE or with the following:
+
+     byte      SSH_MSG_USERAUTH_PK_OK
+     string    public key algorithm name from the request
+     string    public key blob from the request
+
+   To perform actual authentication, the client MAY then send a
+   signature generated using the private key.  The client MAY send the
+   signature directly without first verifying whether the key is
+   acceptable. The signature is sent using the following packet:
+
+     byte      SSH_MSG_USERAUTH_REQUEST
+     string    user name
+     string    service
+     string    "publickey"
+     boolean   TRUE
+     string    public key algorithm name
+     string    public key to be used for authentication
+     string    signature
+
+   Signature is a signature by the corresponding private key over the
+   following data, in the following order:
+
+     string    session identifier
+     byte      SSH_MSG_USERAUTH_REQUEST
+     string    user name
+     string    service
+     string    "publickey"
+     boolean   TRUE
+     string    public key algorithm name
+     string    public key to be used for authentication
+
+   When the server receives this message, it MUST check whether the
+   supplied key is acceptable for authentication, and if so, it MUST
+   check whether the signature is correct.
+
+   If both checks succeed, this method is successful.  Note that the
+   server may require additional authentications.  The server MUST
+   respond with SSH_MSG_USERAUTH_SUCCESS (if no more authentications are
+   needed), or SSH_MSG_USERAUTH_FAILURE (if the request failed, or more
+   authentications are needed).
+
+   The following method-specific message numbers are used by the
+   publickey authentication method.
+
+     /* Key-based */
+     #define SSH_MSG_USERAUTH_PK_OK              60
+
+
+
+
+Ylonen & Moffat          Expires March 2, 2003                  [Page 9]
+
+Internet-Draft        SSH Authentication Protocol         September 2002
+
+
+3.4 Password Authentication Method: password
+
+   Password authentication uses the following packets.  Note that a
+   server MAY request the user to change the password.  All
+   implementations SHOULD support password authentication.
+
+     byte      SSH_MSG_USERAUTH_REQUEST
+     string    user name
+     string    service
+     string    "password"
+     boolean   FALSE
+     string    plaintext password (ISO-10646 UTF-8)
+
+   Note that the password is encoded in ISO-10646 UTF-8.  It is up to
+   the server how it interprets the password and validates it against
+   the password database.  However, if the client reads the password in
+   some other encoding (e.g., ISO 8859-1 (ISO Latin1)), it MUST convert
+   the password to ISO-10646 UTF-8 before transmitting, and the server
+   MUST convert the password to the encoding used on that system for
+   passwords.
+
+   Note that even though the cleartext password is transmitted in the
+   packet, the entire packet is encrypted by the transport layer.  Both
+   the server and the client should check whether the underlying
+   transport layer provides confidentiality (i.e., if encryption is
+   being used).  If no confidentiality is provided (none cipher),
+   password authentication SHOULD be disabled.  If there is no
+   confidentiality or no MAC, password change SHOULD be disabled.
+
+   Normally, the server responds to this message with success or
+   failure. However, if the password has expired the server SHOULD
+   indicate this by responding with SSH_MSG_USERAUTH_PASSWD_CHANGEREQ.
+   In anycase the server MUST NOT allow an expired password to be used
+   for authentication.
+
+     byte      SSH_MSG_USERAUTH_PASSWD_CHANGEREQ
+     string    prompt (ISO-10646 UTF-8)
+     string    language tag (as defined in [RFC3066])
+
+   In this case, the client MAY continue with a different authentication
+   method, or request a new password from the user and retry password
+   authentication using the following message. The client MAY also send
+   this message instead of the normal password authentication request
+   without the server asking for it.
+
+     byte      SSH_MSG_USERAUTH_REQUEST
+     string    user name
+     string    service
+
+
+
+Ylonen & Moffat          Expires March 2, 2003                 [Page 10]
+
+Internet-Draft        SSH Authentication Protocol         September 2002
+
+
+     string    "password"
+     boolean   TRUE
+     string    plaintext old password (ISO-10646 UTF-8)
+     string    plaintext new password (ISO-10646 UTF-8)
+
+   The server must reply to request message with
+   SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE, or another
+   SSH_MSG_USERAUTH_PASSWD_CHANGEREQ.  The meaning of these is as
+   follows:
+
+      SSH_MSG_USERAUTH_SUCCESS The password has been changed, and
+      authentication has been successfully completed.
+
+      SSH_MSG_USERAUTH_FAILURE with partial success The password has
+      been changed, but more authentications are needed.
+
+      SSH_MSG_USERAUTH_FAILURE without partial success The password has
+      not been changed.  Either password changing was not supported, or
+      the old password was bad.  Note that if the server has already
+      sent SSH_MSG_USERAUTH_PASSWD_CHANGEREQ, we know that it supports
+      changing the password.
+
+      SSH_MSG_USERAUTH_CHANGEREQ The password was not changed because
+      the new password was not acceptable (e.g. too easy to guess).
+
+   The following method-specific message numbers are used by the
+   password authentication method.
+
+     #define SSH_MSG_USERAUTH_PASSWD_CHANGEREQ   60
+
+
+3.5 Host-Based Authentication: hostbased
+
+   Some sites wish to allow authentication based on the host where the
+   user is coming from, and the user name on the remote host.  While
+   this form of authentication is not suitable for high-security sites,
+   it can be very convenient in many environments.  This form of
+   authentication is OPTIONAL. When used, special care SHOULD be taken
+   to prevent a regular user from obtaining the private host key.
+
+   The client requests this form of authentication by sending the
+   following message.  It is similar to the UNIX "rhosts" and
+   "hosts.equiv" styles of authentication, except that the identity of
+   the client host is checked more rigorously.
+
+   This method works by having the client send a signature created with
+   the private key of the client host, which the server checks with that
+   host's public key.  Once the client host's identity is established,
+
+
+
+Ylonen & Moffat          Expires March 2, 2003                 [Page 11]
+
+Internet-Draft        SSH Authentication Protocol         September 2002
+
+
+   authorization (but no further authentication) is performed based on
+   the user names on the server and the client, and the client host
+   name.
+
+     byte      SSH_MSG_USERAUTH_REQUEST
+     string    user name
+     string    service
+     string    "hostbased"
+     string    public key algorithm for host key
+     string    public host key and certificates for client host
+     string    client host name (FQDN; US-ASCII)
+     string    user name on the client host (ISO-10646 UTF-8)
+     string    signature
+
+   Public key algorithm names for use in "public key algorithm for host
+   key" are defined in the transport layer specification.  The "public
+   host key for client host" may include certificates.
+
+   Signature is a signature with the private host key of the following
+   data, in this order:
+
+     string    session identifier
+     byte      SSH_MSG_USERAUTH_REQUEST
+     string    user name
+     string    service
+     string    "hostbased"
+     string    public key algorithm for host key
+     string    public host key and certificates for client host
+     string    client host name (FQDN; US-ASCII)
+     string    user name on the client host(ISO-10646 UTF-8)
+
+   The server MUST verify that the host key actually belongs to the
+   client host named in the message, that the given user on that host is
+   allowed to log in, and that the signature is a valid signature on the
+   appropriate value by the given host key.  The server MAY ignore the
+   client user name, if it wants to authenticate only the client host.
+
+   It is RECOMMENDED that whenever possible, the server perform
+   additional checks to verify that the network address obtained from
+   the (untrusted) network matches the given client host name.  This
+   makes exploiting compromised host keys more difficult.  Note that
+   this may require special handling for connections coming through a
+   firewall.
+
+4. Security Considerations
+
+   The purpose of this protocol is to perform client user
+   authentication. It assumed that this runs over a secure transport
+
+
+
+Ylonen & Moffat          Expires March 2, 2003                 [Page 12]
+
+Internet-Draft        SSH Authentication Protocol         September 2002
+
+
+   layer protocol, which has already authenticated the server machine,
+   established an encrypted communications channel, and computed a
+   unique session identifier for this session. The transport layer
+   provides forward secrecy for password authentication and other
+   methods that rely on secret data.
+
+   Full security considerations for this protocol are provided in
+   Section 8 of [SSH-ARCH]
+
+Normative
+
+   [SSH-ARCH]
+              Ylonen, T., "SSH Protocol Architecture", I-D
+              draft-ietf-architecture-15.txt, Oct 2003.
+
+   [SSH-TRANS]
+              Ylonen, T., "SSH Transport Layer Protocol", I-D
+              draft-ietf-transport-17.txt, Oct 2003.
+
+   [SSH-USERAUTH]
+              Ylonen, T., "SSH Authentication Protocol", I-D
+              draft-ietf-userauth-18.txt, Oct 2003.
+
+   [SSH-CONNECT]
+              Ylonen, T., "SSH Connection Protocol", I-D
+              draft-ietf-connect-18.txt, Oct 2003.
+
+   [SSH-NUMBERS]
+              Lehtinen, S. and D. Moffat, "SSH Protocol Assigned
+              Numbers", I-D draft-ietf-secsh-assignednumbers-05.txt, Oct
+              2003.
+
+   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
+              Requirement Levels", BCP 14, RFC 2119, March 1997.
+
+Informative
+
+   [RFC3066]  Alvestrand, H., "Tags for the Identification of
+              Languages", BCP 47, RFC 3066, January 2001.
+
+   [RFC2279]  Yergeau, F., "UTF-8, a transformation format of ISO
+              10646", RFC 2279, January 1998.
+
+
+
+
+
+
+
+
+
+Ylonen & Moffat          Expires March 2, 2003                 [Page 13]
+
+Internet-Draft        SSH Authentication Protocol         September 2002
+
+
+Authors' Addresses
+
+   Tatu Ylonen
+   SSH Communications Security Corp
+   Fredrikinkatu 42
+   HELSINKI  FIN-00100
+   Finland
+
+   EMail: [email protected]
+
+
+   Darren J. Moffat (editor)
+   Sun Microsystems, Inc
+   17 Network Circle
+   Menlo Park  95025
+   USA
+
+   EMail: [email protected]
+
+
+
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+
+Ylonen & Moffat          Expires March 2, 2003                 [Page 14]
+
+Internet-Draft        SSH Authentication Protocol         September 2002
+
+
+Intellectual Property Statement
+
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+
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+
+
+Ylonen & Moffat          Expires March 2, 2003                 [Page 15]
+
+Internet-Draft        SSH Authentication Protocol         September 2002
+
+
+   This document and the information contained herein is provided on an
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+Acknowledgment
+
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